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https://git.postgresql.org/git/postgresql.git
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Commit4800f16a7a
added some sanity checks to ensure we don't accidentally corrupt data, but in one of them we failed to consider the effects of a database upgraded from 9.2 or earlier, where a tuple exclusively locked prior to the upgrade has a slightly different bit pattern. Fix that by using the macro that we fixed in commit74ebba84ae
for similar situations. Reported-by: Alexandre Garcia Reviewed-by: Andres Freund Discussion: https://postgr.es/m/CAPYLKR6yxV4=pfW0Gwij7aPNiiPx+3ib4USVYnbuQdUtmkMaEA@mail.gmail.com Andres suspects that this bug may have wider ranging consequences, but I couldn't find anything.
9333 lines
278 KiB
C
9333 lines
278 KiB
C
/*-------------------------------------------------------------------------
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*
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* heapam.c
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* heap access method code
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*
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* Portions Copyright (c) 1996-2018, PostgreSQL Global Development Group
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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*
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* IDENTIFICATION
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* src/backend/access/heap/heapam.c
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*
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*
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* INTERFACE ROUTINES
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* relation_open - open any relation by relation OID
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* relation_openrv - open any relation specified by a RangeVar
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* relation_close - close any relation
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* heap_open - open a heap relation by relation OID
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* heap_openrv - open a heap relation specified by a RangeVar
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* heap_close - (now just a macro for relation_close)
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* heap_beginscan - begin relation scan
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* heap_rescan - restart a relation scan
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* heap_endscan - end relation scan
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* heap_getnext - retrieve next tuple in scan
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* heap_fetch - retrieve tuple with given tid
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* heap_insert - insert tuple into a relation
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* heap_multi_insert - insert multiple tuples into a relation
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* heap_delete - delete a tuple from a relation
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* heap_update - replace a tuple in a relation with another tuple
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* heap_sync - sync heap, for when no WAL has been written
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*
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* NOTES
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* This file contains the heap_ routines which implement
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* the POSTGRES heap access method used for all POSTGRES
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* relations.
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*
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*-------------------------------------------------------------------------
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*/
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#include "postgres.h"
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#include "access/bufmask.h"
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#include "access/heapam.h"
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#include "access/heapam_xlog.h"
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#include "access/hio.h"
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#include "access/multixact.h"
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#include "access/parallel.h"
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#include "access/relscan.h"
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#include "access/sysattr.h"
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#include "access/transam.h"
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#include "access/tuptoaster.h"
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#include "access/valid.h"
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#include "access/visibilitymap.h"
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#include "access/xact.h"
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#include "access/xlog.h"
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#include "access/xloginsert.h"
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#include "access/xlogutils.h"
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#include "catalog/catalog.h"
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#include "catalog/namespace.h"
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#include "miscadmin.h"
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#include "pgstat.h"
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#include "port/atomics.h"
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#include "storage/bufmgr.h"
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#include "storage/freespace.h"
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#include "storage/lmgr.h"
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#include "storage/predicate.h"
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#include "storage/procarray.h"
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#include "storage/smgr.h"
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#include "storage/spin.h"
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#include "storage/standby.h"
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#include "utils/datum.h"
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#include "utils/inval.h"
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#include "utils/lsyscache.h"
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#include "utils/relcache.h"
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#include "utils/snapmgr.h"
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#include "utils/syscache.h"
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#include "utils/tqual.h"
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/* GUC variable */
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bool synchronize_seqscans = true;
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static HeapScanDesc heap_beginscan_internal(Relation relation,
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Snapshot snapshot,
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int nkeys, ScanKey key,
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ParallelHeapScanDesc parallel_scan,
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bool allow_strat,
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bool allow_sync,
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bool allow_pagemode,
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bool is_bitmapscan,
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bool is_samplescan,
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bool temp_snap);
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static void heap_parallelscan_startblock_init(HeapScanDesc scan);
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static BlockNumber heap_parallelscan_nextpage(HeapScanDesc scan);
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static HeapTuple heap_prepare_insert(Relation relation, HeapTuple tup,
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TransactionId xid, CommandId cid, int options);
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static XLogRecPtr log_heap_update(Relation reln, Buffer oldbuf,
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Buffer newbuf, HeapTuple oldtup,
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HeapTuple newtup, HeapTuple old_key_tup,
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bool all_visible_cleared, bool new_all_visible_cleared);
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static Bitmapset *HeapDetermineModifiedColumns(Relation relation,
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Bitmapset *interesting_cols,
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HeapTuple oldtup, HeapTuple newtup);
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static bool heap_acquire_tuplock(Relation relation, ItemPointer tid,
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LockTupleMode mode, LockWaitPolicy wait_policy,
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bool *have_tuple_lock);
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static void compute_new_xmax_infomask(TransactionId xmax, uint16 old_infomask,
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uint16 old_infomask2, TransactionId add_to_xmax,
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LockTupleMode mode, bool is_update,
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TransactionId *result_xmax, uint16 *result_infomask,
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uint16 *result_infomask2);
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static HTSU_Result heap_lock_updated_tuple(Relation rel, HeapTuple tuple,
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ItemPointer ctid, TransactionId xid,
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LockTupleMode mode);
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static void GetMultiXactIdHintBits(MultiXactId multi, uint16 *new_infomask,
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uint16 *new_infomask2);
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static TransactionId MultiXactIdGetUpdateXid(TransactionId xmax,
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uint16 t_infomask);
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static bool DoesMultiXactIdConflict(MultiXactId multi, uint16 infomask,
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LockTupleMode lockmode);
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static void MultiXactIdWait(MultiXactId multi, MultiXactStatus status, uint16 infomask,
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Relation rel, ItemPointer ctid, XLTW_Oper oper,
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int *remaining);
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static bool ConditionalMultiXactIdWait(MultiXactId multi, MultiXactStatus status,
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uint16 infomask, Relation rel, int *remaining);
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static XLogRecPtr log_heap_new_cid(Relation relation, HeapTuple tup);
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static HeapTuple ExtractReplicaIdentity(Relation rel, HeapTuple tup, bool key_modified,
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bool *copy);
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/*
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* Each tuple lock mode has a corresponding heavyweight lock, and one or two
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* corresponding MultiXactStatuses (one to merely lock tuples, another one to
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* update them). This table (and the macros below) helps us determine the
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* heavyweight lock mode and MultiXactStatus values to use for any particular
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* tuple lock strength.
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*
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* Don't look at lockstatus/updstatus directly! Use get_mxact_status_for_lock
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* instead.
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*/
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static const struct
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{
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LOCKMODE hwlock;
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int lockstatus;
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int updstatus;
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}
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tupleLockExtraInfo[MaxLockTupleMode + 1] =
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{
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{ /* LockTupleKeyShare */
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AccessShareLock,
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MultiXactStatusForKeyShare,
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-1 /* KeyShare does not allow updating tuples */
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},
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{ /* LockTupleShare */
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RowShareLock,
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MultiXactStatusForShare,
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-1 /* Share does not allow updating tuples */
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},
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{ /* LockTupleNoKeyExclusive */
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ExclusiveLock,
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MultiXactStatusForNoKeyUpdate,
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MultiXactStatusNoKeyUpdate
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},
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{ /* LockTupleExclusive */
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AccessExclusiveLock,
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MultiXactStatusForUpdate,
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MultiXactStatusUpdate
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}
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};
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/* Get the LOCKMODE for a given MultiXactStatus */
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#define LOCKMODE_from_mxstatus(status) \
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(tupleLockExtraInfo[TUPLOCK_from_mxstatus((status))].hwlock)
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/*
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* Acquire heavyweight locks on tuples, using a LockTupleMode strength value.
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* This is more readable than having every caller translate it to lock.h's
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* LOCKMODE.
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*/
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#define LockTupleTuplock(rel, tup, mode) \
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LockTuple((rel), (tup), tupleLockExtraInfo[mode].hwlock)
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#define UnlockTupleTuplock(rel, tup, mode) \
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UnlockTuple((rel), (tup), tupleLockExtraInfo[mode].hwlock)
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#define ConditionalLockTupleTuplock(rel, tup, mode) \
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ConditionalLockTuple((rel), (tup), tupleLockExtraInfo[mode].hwlock)
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/*
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* This table maps tuple lock strength values for each particular
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* MultiXactStatus value.
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*/
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static const int MultiXactStatusLock[MaxMultiXactStatus + 1] =
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{
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LockTupleKeyShare, /* ForKeyShare */
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LockTupleShare, /* ForShare */
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LockTupleNoKeyExclusive, /* ForNoKeyUpdate */
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LockTupleExclusive, /* ForUpdate */
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LockTupleNoKeyExclusive, /* NoKeyUpdate */
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LockTupleExclusive /* Update */
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};
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/* Get the LockTupleMode for a given MultiXactStatus */
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#define TUPLOCK_from_mxstatus(status) \
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(MultiXactStatusLock[(status)])
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/* ----------------------------------------------------------------
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* heap support routines
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* ----------------------------------------------------------------
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*/
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/* ----------------
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* initscan - scan code common to heap_beginscan and heap_rescan
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* ----------------
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*/
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static void
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initscan(HeapScanDesc scan, ScanKey key, bool keep_startblock)
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{
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bool allow_strat;
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bool allow_sync;
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/*
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* Determine the number of blocks we have to scan.
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*
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* It is sufficient to do this once at scan start, since any tuples added
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* while the scan is in progress will be invisible to my snapshot anyway.
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* (That is not true when using a non-MVCC snapshot. However, we couldn't
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* guarantee to return tuples added after scan start anyway, since they
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* might go into pages we already scanned. To guarantee consistent
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* results for a non-MVCC snapshot, the caller must hold some higher-level
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* lock that ensures the interesting tuple(s) won't change.)
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*/
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if (scan->rs_parallel != NULL)
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scan->rs_nblocks = scan->rs_parallel->phs_nblocks;
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else
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scan->rs_nblocks = RelationGetNumberOfBlocks(scan->rs_rd);
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/*
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* If the table is large relative to NBuffers, use a bulk-read access
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* strategy and enable synchronized scanning (see syncscan.c). Although
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* the thresholds for these features could be different, we make them the
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* same so that there are only two behaviors to tune rather than four.
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* (However, some callers need to be able to disable one or both of these
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* behaviors, independently of the size of the table; also there is a GUC
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* variable that can disable synchronized scanning.)
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*
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* Note that heap_parallelscan_initialize has a very similar test; if you
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* change this, consider changing that one, too.
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*/
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if (!RelationUsesLocalBuffers(scan->rs_rd) &&
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scan->rs_nblocks > NBuffers / 4)
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{
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allow_strat = scan->rs_allow_strat;
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allow_sync = scan->rs_allow_sync;
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}
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else
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allow_strat = allow_sync = false;
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if (allow_strat)
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{
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/* During a rescan, keep the previous strategy object. */
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if (scan->rs_strategy == NULL)
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scan->rs_strategy = GetAccessStrategy(BAS_BULKREAD);
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}
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else
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{
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if (scan->rs_strategy != NULL)
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FreeAccessStrategy(scan->rs_strategy);
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scan->rs_strategy = NULL;
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}
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if (scan->rs_parallel != NULL)
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{
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/* For parallel scan, believe whatever ParallelHeapScanDesc says. */
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scan->rs_syncscan = scan->rs_parallel->phs_syncscan;
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}
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else if (keep_startblock)
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{
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/*
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* When rescanning, we want to keep the previous startblock setting,
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* so that rewinding a cursor doesn't generate surprising results.
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* Reset the active syncscan setting, though.
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*/
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scan->rs_syncscan = (allow_sync && synchronize_seqscans);
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}
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else if (allow_sync && synchronize_seqscans)
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{
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scan->rs_syncscan = true;
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scan->rs_startblock = ss_get_location(scan->rs_rd, scan->rs_nblocks);
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}
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else
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{
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scan->rs_syncscan = false;
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scan->rs_startblock = 0;
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}
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scan->rs_numblocks = InvalidBlockNumber;
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scan->rs_inited = false;
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scan->rs_ctup.t_data = NULL;
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ItemPointerSetInvalid(&scan->rs_ctup.t_self);
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scan->rs_cbuf = InvalidBuffer;
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scan->rs_cblock = InvalidBlockNumber;
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/* page-at-a-time fields are always invalid when not rs_inited */
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/*
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* copy the scan key, if appropriate
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*/
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if (key != NULL)
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memcpy(scan->rs_key, key, scan->rs_nkeys * sizeof(ScanKeyData));
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/*
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* Currently, we don't have a stats counter for bitmap heap scans (but the
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* underlying bitmap index scans will be counted) or sample scans (we only
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* update stats for tuple fetches there)
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*/
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if (!scan->rs_bitmapscan && !scan->rs_samplescan)
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pgstat_count_heap_scan(scan->rs_rd);
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}
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/*
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* heap_setscanlimits - restrict range of a heapscan
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*
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* startBlk is the page to start at
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* numBlks is number of pages to scan (InvalidBlockNumber means "all")
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*/
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void
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heap_setscanlimits(HeapScanDesc scan, BlockNumber startBlk, BlockNumber numBlks)
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{
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Assert(!scan->rs_inited); /* else too late to change */
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Assert(!scan->rs_syncscan); /* else rs_startblock is significant */
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/* Check startBlk is valid (but allow case of zero blocks...) */
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Assert(startBlk == 0 || startBlk < scan->rs_nblocks);
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scan->rs_startblock = startBlk;
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scan->rs_numblocks = numBlks;
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}
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/*
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* heapgetpage - subroutine for heapgettup()
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*
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* This routine reads and pins the specified page of the relation.
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* In page-at-a-time mode it performs additional work, namely determining
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* which tuples on the page are visible.
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*/
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void
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heapgetpage(HeapScanDesc scan, BlockNumber page)
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{
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Buffer buffer;
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Snapshot snapshot;
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Page dp;
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int lines;
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int ntup;
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OffsetNumber lineoff;
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ItemId lpp;
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bool all_visible;
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Assert(page < scan->rs_nblocks);
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/* release previous scan buffer, if any */
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if (BufferIsValid(scan->rs_cbuf))
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{
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ReleaseBuffer(scan->rs_cbuf);
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scan->rs_cbuf = InvalidBuffer;
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}
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/*
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* Be sure to check for interrupts at least once per page. Checks at
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* higher code levels won't be able to stop a seqscan that encounters many
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* pages' worth of consecutive dead tuples.
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*/
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CHECK_FOR_INTERRUPTS();
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/* read page using selected strategy */
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scan->rs_cbuf = ReadBufferExtended(scan->rs_rd, MAIN_FORKNUM, page,
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RBM_NORMAL, scan->rs_strategy);
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scan->rs_cblock = page;
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if (!scan->rs_pageatatime)
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return;
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buffer = scan->rs_cbuf;
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snapshot = scan->rs_snapshot;
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/*
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* Prune and repair fragmentation for the whole page, if possible.
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*/
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heap_page_prune_opt(scan->rs_rd, buffer);
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/*
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* We must hold share lock on the buffer content while examining tuple
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* visibility. Afterwards, however, the tuples we have found to be
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* visible are guaranteed good as long as we hold the buffer pin.
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*/
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LockBuffer(buffer, BUFFER_LOCK_SHARE);
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dp = BufferGetPage(buffer);
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TestForOldSnapshot(snapshot, scan->rs_rd, dp);
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lines = PageGetMaxOffsetNumber(dp);
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ntup = 0;
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/*
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* If the all-visible flag indicates that all tuples on the page are
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* visible to everyone, we can skip the per-tuple visibility tests.
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*
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* Note: In hot standby, a tuple that's already visible to all
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* transactions in the master might still be invisible to a read-only
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* transaction in the standby. We partly handle this problem by tracking
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* the minimum xmin of visible tuples as the cut-off XID while marking a
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* page all-visible on master and WAL log that along with the visibility
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* map SET operation. In hot standby, we wait for (or abort) all
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* transactions that can potentially may not see one or more tuples on the
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* page. That's how index-only scans work fine in hot standby. A crucial
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* difference between index-only scans and heap scans is that the
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* index-only scan completely relies on the visibility map where as heap
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* scan looks at the page-level PD_ALL_VISIBLE flag. We are not sure if
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* the page-level flag can be trusted in the same way, because it might
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* get propagated somehow without being explicitly WAL-logged, e.g. via a
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* full page write. Until we can prove that beyond doubt, let's check each
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* tuple for visibility the hard way.
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*/
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all_visible = PageIsAllVisible(dp) && !snapshot->takenDuringRecovery;
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for (lineoff = FirstOffsetNumber, lpp = PageGetItemId(dp, lineoff);
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lineoff <= lines;
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lineoff++, lpp++)
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{
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if (ItemIdIsNormal(lpp))
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{
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HeapTupleData loctup;
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bool valid;
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loctup.t_tableOid = RelationGetRelid(scan->rs_rd);
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loctup.t_data = (HeapTupleHeader) PageGetItem((Page) dp, lpp);
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loctup.t_len = ItemIdGetLength(lpp);
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ItemPointerSet(&(loctup.t_self), page, lineoff);
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if (all_visible)
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valid = true;
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else
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valid = HeapTupleSatisfiesVisibility(&loctup, snapshot, buffer);
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CheckForSerializableConflictOut(valid, scan->rs_rd, &loctup,
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buffer, snapshot);
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if (valid)
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scan->rs_vistuples[ntup++] = lineoff;
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}
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}
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LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
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Assert(ntup <= MaxHeapTuplesPerPage);
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scan->rs_ntuples = ntup;
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}
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/* ----------------
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* heapgettup - fetch next heap tuple
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*
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* Initialize the scan if not already done; then advance to the next
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* tuple as indicated by "dir"; return the next tuple in scan->rs_ctup,
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* or set scan->rs_ctup.t_data = NULL if no more tuples.
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*
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* dir == NoMovementScanDirection means "re-fetch the tuple indicated
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* by scan->rs_ctup".
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*
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* Note: the reason nkeys/key are passed separately, even though they are
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* kept in the scan descriptor, is that the caller may not want us to check
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* the scankeys.
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*
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* Note: when we fall off the end of the scan in either direction, we
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* reset rs_inited. This means that a further request with the same
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* scan direction will restart the scan, which is a bit odd, but a
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* request with the opposite scan direction will start a fresh scan
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* in the proper direction. The latter is required behavior for cursors,
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* while the former case is generally undefined behavior in Postgres
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* so we don't care too much.
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* ----------------
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*/
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static void
|
|
heapgettup(HeapScanDesc scan,
|
|
ScanDirection dir,
|
|
int nkeys,
|
|
ScanKey key)
|
|
{
|
|
HeapTuple tuple = &(scan->rs_ctup);
|
|
Snapshot snapshot = scan->rs_snapshot;
|
|
bool backward = ScanDirectionIsBackward(dir);
|
|
BlockNumber page;
|
|
bool finished;
|
|
Page dp;
|
|
int lines;
|
|
OffsetNumber lineoff;
|
|
int linesleft;
|
|
ItemId lpp;
|
|
|
|
/*
|
|
* calculate next starting lineoff, given scan direction
|
|
*/
|
|
if (ScanDirectionIsForward(dir))
|
|
{
|
|
if (!scan->rs_inited)
|
|
{
|
|
/*
|
|
* return null immediately if relation is empty
|
|
*/
|
|
if (scan->rs_nblocks == 0 || scan->rs_numblocks == 0)
|
|
{
|
|
Assert(!BufferIsValid(scan->rs_cbuf));
|
|
tuple->t_data = NULL;
|
|
return;
|
|
}
|
|
if (scan->rs_parallel != NULL)
|
|
{
|
|
heap_parallelscan_startblock_init(scan);
|
|
|
|
page = heap_parallelscan_nextpage(scan);
|
|
|
|
/* Other processes might have already finished the scan. */
|
|
if (page == InvalidBlockNumber)
|
|
{
|
|
Assert(!BufferIsValid(scan->rs_cbuf));
|
|
tuple->t_data = NULL;
|
|
return;
|
|
}
|
|
}
|
|
else
|
|
page = scan->rs_startblock; /* first page */
|
|
heapgetpage(scan, page);
|
|
lineoff = FirstOffsetNumber; /* first offnum */
|
|
scan->rs_inited = true;
|
|
}
|
|
else
|
|
{
|
|
/* continue from previously returned page/tuple */
|
|
page = scan->rs_cblock; /* current page */
|
|
lineoff = /* next offnum */
|
|
OffsetNumberNext(ItemPointerGetOffsetNumber(&(tuple->t_self)));
|
|
}
|
|
|
|
LockBuffer(scan->rs_cbuf, BUFFER_LOCK_SHARE);
|
|
|
|
dp = BufferGetPage(scan->rs_cbuf);
|
|
TestForOldSnapshot(snapshot, scan->rs_rd, dp);
|
|
lines = PageGetMaxOffsetNumber(dp);
|
|
/* page and lineoff now reference the physically next tid */
|
|
|
|
linesleft = lines - lineoff + 1;
|
|
}
|
|
else if (backward)
|
|
{
|
|
/* backward parallel scan not supported */
|
|
Assert(scan->rs_parallel == NULL);
|
|
|
|
if (!scan->rs_inited)
|
|
{
|
|
/*
|
|
* return null immediately if relation is empty
|
|
*/
|
|
if (scan->rs_nblocks == 0 || scan->rs_numblocks == 0)
|
|
{
|
|
Assert(!BufferIsValid(scan->rs_cbuf));
|
|
tuple->t_data = NULL;
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* Disable reporting to syncscan logic in a backwards scan; it's
|
|
* not very likely anyone else is doing the same thing at the same
|
|
* time, and much more likely that we'll just bollix things for
|
|
* forward scanners.
|
|
*/
|
|
scan->rs_syncscan = false;
|
|
/* start from last page of the scan */
|
|
if (scan->rs_startblock > 0)
|
|
page = scan->rs_startblock - 1;
|
|
else
|
|
page = scan->rs_nblocks - 1;
|
|
heapgetpage(scan, page);
|
|
}
|
|
else
|
|
{
|
|
/* continue from previously returned page/tuple */
|
|
page = scan->rs_cblock; /* current page */
|
|
}
|
|
|
|
LockBuffer(scan->rs_cbuf, BUFFER_LOCK_SHARE);
|
|
|
|
dp = BufferGetPage(scan->rs_cbuf);
|
|
TestForOldSnapshot(snapshot, scan->rs_rd, dp);
|
|
lines = PageGetMaxOffsetNumber(dp);
|
|
|
|
if (!scan->rs_inited)
|
|
{
|
|
lineoff = lines; /* final offnum */
|
|
scan->rs_inited = true;
|
|
}
|
|
else
|
|
{
|
|
lineoff = /* previous offnum */
|
|
OffsetNumberPrev(ItemPointerGetOffsetNumber(&(tuple->t_self)));
|
|
}
|
|
/* page and lineoff now reference the physically previous tid */
|
|
|
|
linesleft = lineoff;
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* ``no movement'' scan direction: refetch prior tuple
|
|
*/
|
|
if (!scan->rs_inited)
|
|
{
|
|
Assert(!BufferIsValid(scan->rs_cbuf));
|
|
tuple->t_data = NULL;
|
|
return;
|
|
}
|
|
|
|
page = ItemPointerGetBlockNumber(&(tuple->t_self));
|
|
if (page != scan->rs_cblock)
|
|
heapgetpage(scan, page);
|
|
|
|
/* Since the tuple was previously fetched, needn't lock page here */
|
|
dp = BufferGetPage(scan->rs_cbuf);
|
|
TestForOldSnapshot(snapshot, scan->rs_rd, dp);
|
|
lineoff = ItemPointerGetOffsetNumber(&(tuple->t_self));
|
|
lpp = PageGetItemId(dp, lineoff);
|
|
Assert(ItemIdIsNormal(lpp));
|
|
|
|
tuple->t_data = (HeapTupleHeader) PageGetItem((Page) dp, lpp);
|
|
tuple->t_len = ItemIdGetLength(lpp);
|
|
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* advance the scan until we find a qualifying tuple or run out of stuff
|
|
* to scan
|
|
*/
|
|
lpp = PageGetItemId(dp, lineoff);
|
|
for (;;)
|
|
{
|
|
while (linesleft > 0)
|
|
{
|
|
if (ItemIdIsNormal(lpp))
|
|
{
|
|
bool valid;
|
|
|
|
tuple->t_data = (HeapTupleHeader) PageGetItem((Page) dp, lpp);
|
|
tuple->t_len = ItemIdGetLength(lpp);
|
|
ItemPointerSet(&(tuple->t_self), page, lineoff);
|
|
|
|
/*
|
|
* if current tuple qualifies, return it.
|
|
*/
|
|
valid = HeapTupleSatisfiesVisibility(tuple,
|
|
snapshot,
|
|
scan->rs_cbuf);
|
|
|
|
CheckForSerializableConflictOut(valid, scan->rs_rd, tuple,
|
|
scan->rs_cbuf, snapshot);
|
|
|
|
if (valid && key != NULL)
|
|
HeapKeyTest(tuple, RelationGetDescr(scan->rs_rd),
|
|
nkeys, key, valid);
|
|
|
|
if (valid)
|
|
{
|
|
LockBuffer(scan->rs_cbuf, BUFFER_LOCK_UNLOCK);
|
|
return;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* otherwise move to the next item on the page
|
|
*/
|
|
--linesleft;
|
|
if (backward)
|
|
{
|
|
--lpp; /* move back in this page's ItemId array */
|
|
--lineoff;
|
|
}
|
|
else
|
|
{
|
|
++lpp; /* move forward in this page's ItemId array */
|
|
++lineoff;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* if we get here, it means we've exhausted the items on this page and
|
|
* it's time to move to the next.
|
|
*/
|
|
LockBuffer(scan->rs_cbuf, BUFFER_LOCK_UNLOCK);
|
|
|
|
/*
|
|
* advance to next/prior page and detect end of scan
|
|
*/
|
|
if (backward)
|
|
{
|
|
finished = (page == scan->rs_startblock) ||
|
|
(scan->rs_numblocks != InvalidBlockNumber ? --scan->rs_numblocks == 0 : false);
|
|
if (page == 0)
|
|
page = scan->rs_nblocks;
|
|
page--;
|
|
}
|
|
else if (scan->rs_parallel != NULL)
|
|
{
|
|
page = heap_parallelscan_nextpage(scan);
|
|
finished = (page == InvalidBlockNumber);
|
|
}
|
|
else
|
|
{
|
|
page++;
|
|
if (page >= scan->rs_nblocks)
|
|
page = 0;
|
|
finished = (page == scan->rs_startblock) ||
|
|
(scan->rs_numblocks != InvalidBlockNumber ? --scan->rs_numblocks == 0 : false);
|
|
|
|
/*
|
|
* Report our new scan position for synchronization purposes. We
|
|
* don't do that when moving backwards, however. That would just
|
|
* mess up any other forward-moving scanners.
|
|
*
|
|
* Note: we do this before checking for end of scan so that the
|
|
* final state of the position hint is back at the start of the
|
|
* rel. That's not strictly necessary, but otherwise when you run
|
|
* the same query multiple times the starting position would shift
|
|
* a little bit backwards on every invocation, which is confusing.
|
|
* We don't guarantee any specific ordering in general, though.
|
|
*/
|
|
if (scan->rs_syncscan)
|
|
ss_report_location(scan->rs_rd, page);
|
|
}
|
|
|
|
/*
|
|
* return NULL if we've exhausted all the pages
|
|
*/
|
|
if (finished)
|
|
{
|
|
if (BufferIsValid(scan->rs_cbuf))
|
|
ReleaseBuffer(scan->rs_cbuf);
|
|
scan->rs_cbuf = InvalidBuffer;
|
|
scan->rs_cblock = InvalidBlockNumber;
|
|
tuple->t_data = NULL;
|
|
scan->rs_inited = false;
|
|
return;
|
|
}
|
|
|
|
heapgetpage(scan, page);
|
|
|
|
LockBuffer(scan->rs_cbuf, BUFFER_LOCK_SHARE);
|
|
|
|
dp = BufferGetPage(scan->rs_cbuf);
|
|
TestForOldSnapshot(snapshot, scan->rs_rd, dp);
|
|
lines = PageGetMaxOffsetNumber((Page) dp);
|
|
linesleft = lines;
|
|
if (backward)
|
|
{
|
|
lineoff = lines;
|
|
lpp = PageGetItemId(dp, lines);
|
|
}
|
|
else
|
|
{
|
|
lineoff = FirstOffsetNumber;
|
|
lpp = PageGetItemId(dp, FirstOffsetNumber);
|
|
}
|
|
}
|
|
}
|
|
|
|
/* ----------------
|
|
* heapgettup_pagemode - fetch next heap tuple in page-at-a-time mode
|
|
*
|
|
* Same API as heapgettup, but used in page-at-a-time mode
|
|
*
|
|
* The internal logic is much the same as heapgettup's too, but there are some
|
|
* differences: we do not take the buffer content lock (that only needs to
|
|
* happen inside heapgetpage), and we iterate through just the tuples listed
|
|
* in rs_vistuples[] rather than all tuples on the page. Notice that
|
|
* lineindex is 0-based, where the corresponding loop variable lineoff in
|
|
* heapgettup is 1-based.
|
|
* ----------------
|
|
*/
|
|
static void
|
|
heapgettup_pagemode(HeapScanDesc scan,
|
|
ScanDirection dir,
|
|
int nkeys,
|
|
ScanKey key)
|
|
{
|
|
HeapTuple tuple = &(scan->rs_ctup);
|
|
bool backward = ScanDirectionIsBackward(dir);
|
|
BlockNumber page;
|
|
bool finished;
|
|
Page dp;
|
|
int lines;
|
|
int lineindex;
|
|
OffsetNumber lineoff;
|
|
int linesleft;
|
|
ItemId lpp;
|
|
|
|
/*
|
|
* calculate next starting lineindex, given scan direction
|
|
*/
|
|
if (ScanDirectionIsForward(dir))
|
|
{
|
|
if (!scan->rs_inited)
|
|
{
|
|
/*
|
|
* return null immediately if relation is empty
|
|
*/
|
|
if (scan->rs_nblocks == 0 || scan->rs_numblocks == 0)
|
|
{
|
|
Assert(!BufferIsValid(scan->rs_cbuf));
|
|
tuple->t_data = NULL;
|
|
return;
|
|
}
|
|
if (scan->rs_parallel != NULL)
|
|
{
|
|
heap_parallelscan_startblock_init(scan);
|
|
|
|
page = heap_parallelscan_nextpage(scan);
|
|
|
|
/* Other processes might have already finished the scan. */
|
|
if (page == InvalidBlockNumber)
|
|
{
|
|
Assert(!BufferIsValid(scan->rs_cbuf));
|
|
tuple->t_data = NULL;
|
|
return;
|
|
}
|
|
}
|
|
else
|
|
page = scan->rs_startblock; /* first page */
|
|
heapgetpage(scan, page);
|
|
lineindex = 0;
|
|
scan->rs_inited = true;
|
|
}
|
|
else
|
|
{
|
|
/* continue from previously returned page/tuple */
|
|
page = scan->rs_cblock; /* current page */
|
|
lineindex = scan->rs_cindex + 1;
|
|
}
|
|
|
|
dp = BufferGetPage(scan->rs_cbuf);
|
|
TestForOldSnapshot(scan->rs_snapshot, scan->rs_rd, dp);
|
|
lines = scan->rs_ntuples;
|
|
/* page and lineindex now reference the next visible tid */
|
|
|
|
linesleft = lines - lineindex;
|
|
}
|
|
else if (backward)
|
|
{
|
|
/* backward parallel scan not supported */
|
|
Assert(scan->rs_parallel == NULL);
|
|
|
|
if (!scan->rs_inited)
|
|
{
|
|
/*
|
|
* return null immediately if relation is empty
|
|
*/
|
|
if (scan->rs_nblocks == 0 || scan->rs_numblocks == 0)
|
|
{
|
|
Assert(!BufferIsValid(scan->rs_cbuf));
|
|
tuple->t_data = NULL;
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* Disable reporting to syncscan logic in a backwards scan; it's
|
|
* not very likely anyone else is doing the same thing at the same
|
|
* time, and much more likely that we'll just bollix things for
|
|
* forward scanners.
|
|
*/
|
|
scan->rs_syncscan = false;
|
|
/* start from last page of the scan */
|
|
if (scan->rs_startblock > 0)
|
|
page = scan->rs_startblock - 1;
|
|
else
|
|
page = scan->rs_nblocks - 1;
|
|
heapgetpage(scan, page);
|
|
}
|
|
else
|
|
{
|
|
/* continue from previously returned page/tuple */
|
|
page = scan->rs_cblock; /* current page */
|
|
}
|
|
|
|
dp = BufferGetPage(scan->rs_cbuf);
|
|
TestForOldSnapshot(scan->rs_snapshot, scan->rs_rd, dp);
|
|
lines = scan->rs_ntuples;
|
|
|
|
if (!scan->rs_inited)
|
|
{
|
|
lineindex = lines - 1;
|
|
scan->rs_inited = true;
|
|
}
|
|
else
|
|
{
|
|
lineindex = scan->rs_cindex - 1;
|
|
}
|
|
/* page and lineindex now reference the previous visible tid */
|
|
|
|
linesleft = lineindex + 1;
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* ``no movement'' scan direction: refetch prior tuple
|
|
*/
|
|
if (!scan->rs_inited)
|
|
{
|
|
Assert(!BufferIsValid(scan->rs_cbuf));
|
|
tuple->t_data = NULL;
|
|
return;
|
|
}
|
|
|
|
page = ItemPointerGetBlockNumber(&(tuple->t_self));
|
|
if (page != scan->rs_cblock)
|
|
heapgetpage(scan, page);
|
|
|
|
/* Since the tuple was previously fetched, needn't lock page here */
|
|
dp = BufferGetPage(scan->rs_cbuf);
|
|
TestForOldSnapshot(scan->rs_snapshot, scan->rs_rd, dp);
|
|
lineoff = ItemPointerGetOffsetNumber(&(tuple->t_self));
|
|
lpp = PageGetItemId(dp, lineoff);
|
|
Assert(ItemIdIsNormal(lpp));
|
|
|
|
tuple->t_data = (HeapTupleHeader) PageGetItem((Page) dp, lpp);
|
|
tuple->t_len = ItemIdGetLength(lpp);
|
|
|
|
/* check that rs_cindex is in sync */
|
|
Assert(scan->rs_cindex < scan->rs_ntuples);
|
|
Assert(lineoff == scan->rs_vistuples[scan->rs_cindex]);
|
|
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* advance the scan until we find a qualifying tuple or run out of stuff
|
|
* to scan
|
|
*/
|
|
for (;;)
|
|
{
|
|
while (linesleft > 0)
|
|
{
|
|
lineoff = scan->rs_vistuples[lineindex];
|
|
lpp = PageGetItemId(dp, lineoff);
|
|
Assert(ItemIdIsNormal(lpp));
|
|
|
|
tuple->t_data = (HeapTupleHeader) PageGetItem((Page) dp, lpp);
|
|
tuple->t_len = ItemIdGetLength(lpp);
|
|
ItemPointerSet(&(tuple->t_self), page, lineoff);
|
|
|
|
/*
|
|
* if current tuple qualifies, return it.
|
|
*/
|
|
if (key != NULL)
|
|
{
|
|
bool valid;
|
|
|
|
HeapKeyTest(tuple, RelationGetDescr(scan->rs_rd),
|
|
nkeys, key, valid);
|
|
if (valid)
|
|
{
|
|
scan->rs_cindex = lineindex;
|
|
return;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
scan->rs_cindex = lineindex;
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* otherwise move to the next item on the page
|
|
*/
|
|
--linesleft;
|
|
if (backward)
|
|
--lineindex;
|
|
else
|
|
++lineindex;
|
|
}
|
|
|
|
/*
|
|
* if we get here, it means we've exhausted the items on this page and
|
|
* it's time to move to the next.
|
|
*/
|
|
if (backward)
|
|
{
|
|
finished = (page == scan->rs_startblock) ||
|
|
(scan->rs_numblocks != InvalidBlockNumber ? --scan->rs_numblocks == 0 : false);
|
|
if (page == 0)
|
|
page = scan->rs_nblocks;
|
|
page--;
|
|
}
|
|
else if (scan->rs_parallel != NULL)
|
|
{
|
|
page = heap_parallelscan_nextpage(scan);
|
|
finished = (page == InvalidBlockNumber);
|
|
}
|
|
else
|
|
{
|
|
page++;
|
|
if (page >= scan->rs_nblocks)
|
|
page = 0;
|
|
finished = (page == scan->rs_startblock) ||
|
|
(scan->rs_numblocks != InvalidBlockNumber ? --scan->rs_numblocks == 0 : false);
|
|
|
|
/*
|
|
* Report our new scan position for synchronization purposes. We
|
|
* don't do that when moving backwards, however. That would just
|
|
* mess up any other forward-moving scanners.
|
|
*
|
|
* Note: we do this before checking for end of scan so that the
|
|
* final state of the position hint is back at the start of the
|
|
* rel. That's not strictly necessary, but otherwise when you run
|
|
* the same query multiple times the starting position would shift
|
|
* a little bit backwards on every invocation, which is confusing.
|
|
* We don't guarantee any specific ordering in general, though.
|
|
*/
|
|
if (scan->rs_syncscan)
|
|
ss_report_location(scan->rs_rd, page);
|
|
}
|
|
|
|
/*
|
|
* return NULL if we've exhausted all the pages
|
|
*/
|
|
if (finished)
|
|
{
|
|
if (BufferIsValid(scan->rs_cbuf))
|
|
ReleaseBuffer(scan->rs_cbuf);
|
|
scan->rs_cbuf = InvalidBuffer;
|
|
scan->rs_cblock = InvalidBlockNumber;
|
|
tuple->t_data = NULL;
|
|
scan->rs_inited = false;
|
|
return;
|
|
}
|
|
|
|
heapgetpage(scan, page);
|
|
|
|
dp = BufferGetPage(scan->rs_cbuf);
|
|
TestForOldSnapshot(scan->rs_snapshot, scan->rs_rd, dp);
|
|
lines = scan->rs_ntuples;
|
|
linesleft = lines;
|
|
if (backward)
|
|
lineindex = lines - 1;
|
|
else
|
|
lineindex = 0;
|
|
}
|
|
}
|
|
|
|
|
|
#if defined(DISABLE_COMPLEX_MACRO)
|
|
/*
|
|
* This is formatted so oddly so that the correspondence to the macro
|
|
* definition in access/htup_details.h is maintained.
|
|
*/
|
|
Datum
|
|
fastgetattr(HeapTuple tup, int attnum, TupleDesc tupleDesc,
|
|
bool *isnull)
|
|
{
|
|
return (
|
|
(attnum) > 0 ?
|
|
(
|
|
(*(isnull) = false),
|
|
HeapTupleNoNulls(tup) ?
|
|
(
|
|
TupleDescAttr((tupleDesc), (attnum) - 1)->attcacheoff >= 0 ?
|
|
(
|
|
fetchatt(TupleDescAttr((tupleDesc), (attnum) - 1),
|
|
(char *) (tup)->t_data + (tup)->t_data->t_hoff +
|
|
TupleDescAttr((tupleDesc), (attnum) - 1)->attcacheoff)
|
|
)
|
|
:
|
|
nocachegetattr((tup), (attnum), (tupleDesc))
|
|
)
|
|
:
|
|
(
|
|
att_isnull((attnum) - 1, (tup)->t_data->t_bits) ?
|
|
(
|
|
(*(isnull) = true),
|
|
(Datum) NULL
|
|
)
|
|
:
|
|
(
|
|
nocachegetattr((tup), (attnum), (tupleDesc))
|
|
)
|
|
)
|
|
)
|
|
:
|
|
(
|
|
(Datum) NULL
|
|
)
|
|
);
|
|
}
|
|
#endif /* defined(DISABLE_COMPLEX_MACRO) */
|
|
|
|
|
|
/* ----------------------------------------------------------------
|
|
* heap access method interface
|
|
* ----------------------------------------------------------------
|
|
*/
|
|
|
|
/* ----------------
|
|
* relation_open - open any relation by relation OID
|
|
*
|
|
* If lockmode is not "NoLock", the specified kind of lock is
|
|
* obtained on the relation. (Generally, NoLock should only be
|
|
* used if the caller knows it has some appropriate lock on the
|
|
* relation already.)
|
|
*
|
|
* An error is raised if the relation does not exist.
|
|
*
|
|
* NB: a "relation" is anything with a pg_class entry. The caller is
|
|
* expected to check whether the relkind is something it can handle.
|
|
* ----------------
|
|
*/
|
|
Relation
|
|
relation_open(Oid relationId, LOCKMODE lockmode)
|
|
{
|
|
Relation r;
|
|
|
|
Assert(lockmode >= NoLock && lockmode < MAX_LOCKMODES);
|
|
|
|
/* Get the lock before trying to open the relcache entry */
|
|
if (lockmode != NoLock)
|
|
LockRelationOid(relationId, lockmode);
|
|
|
|
/* The relcache does all the real work... */
|
|
r = RelationIdGetRelation(relationId);
|
|
|
|
if (!RelationIsValid(r))
|
|
elog(ERROR, "could not open relation with OID %u", relationId);
|
|
|
|
/* Make note that we've accessed a temporary relation */
|
|
if (RelationUsesLocalBuffers(r))
|
|
MyXactFlags |= XACT_FLAGS_ACCESSEDTEMPREL;
|
|
|
|
pgstat_initstats(r);
|
|
|
|
return r;
|
|
}
|
|
|
|
/* ----------------
|
|
* try_relation_open - open any relation by relation OID
|
|
*
|
|
* Same as relation_open, except return NULL instead of failing
|
|
* if the relation does not exist.
|
|
* ----------------
|
|
*/
|
|
Relation
|
|
try_relation_open(Oid relationId, LOCKMODE lockmode)
|
|
{
|
|
Relation r;
|
|
|
|
Assert(lockmode >= NoLock && lockmode < MAX_LOCKMODES);
|
|
|
|
/* Get the lock first */
|
|
if (lockmode != NoLock)
|
|
LockRelationOid(relationId, lockmode);
|
|
|
|
/*
|
|
* Now that we have the lock, probe to see if the relation really exists
|
|
* or not.
|
|
*/
|
|
if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(relationId)))
|
|
{
|
|
/* Release useless lock */
|
|
if (lockmode != NoLock)
|
|
UnlockRelationOid(relationId, lockmode);
|
|
|
|
return NULL;
|
|
}
|
|
|
|
/* Should be safe to do a relcache load */
|
|
r = RelationIdGetRelation(relationId);
|
|
|
|
if (!RelationIsValid(r))
|
|
elog(ERROR, "could not open relation with OID %u", relationId);
|
|
|
|
/* Make note that we've accessed a temporary relation */
|
|
if (RelationUsesLocalBuffers(r))
|
|
MyXactFlags |= XACT_FLAGS_ACCESSEDTEMPREL;
|
|
|
|
pgstat_initstats(r);
|
|
|
|
return r;
|
|
}
|
|
|
|
/* ----------------
|
|
* relation_openrv - open any relation specified by a RangeVar
|
|
*
|
|
* Same as relation_open, but the relation is specified by a RangeVar.
|
|
* ----------------
|
|
*/
|
|
Relation
|
|
relation_openrv(const RangeVar *relation, LOCKMODE lockmode)
|
|
{
|
|
Oid relOid;
|
|
|
|
/*
|
|
* Check for shared-cache-inval messages before trying to open the
|
|
* relation. This is needed even if we already hold a lock on the
|
|
* relation, because GRANT/REVOKE are executed without taking any lock on
|
|
* the target relation, and we want to be sure we see current ACL
|
|
* information. We can skip this if asked for NoLock, on the assumption
|
|
* that such a call is not the first one in the current command, and so we
|
|
* should be reasonably up-to-date already. (XXX this all could stand to
|
|
* be redesigned, but for the moment we'll keep doing this like it's been
|
|
* done historically.)
|
|
*/
|
|
if (lockmode != NoLock)
|
|
AcceptInvalidationMessages();
|
|
|
|
/* Look up and lock the appropriate relation using namespace search */
|
|
relOid = RangeVarGetRelid(relation, lockmode, false);
|
|
|
|
/* Let relation_open do the rest */
|
|
return relation_open(relOid, NoLock);
|
|
}
|
|
|
|
/* ----------------
|
|
* relation_openrv_extended - open any relation specified by a RangeVar
|
|
*
|
|
* Same as relation_openrv, but with an additional missing_ok argument
|
|
* allowing a NULL return rather than an error if the relation is not
|
|
* found. (Note that some other causes, such as permissions problems,
|
|
* will still result in an ereport.)
|
|
* ----------------
|
|
*/
|
|
Relation
|
|
relation_openrv_extended(const RangeVar *relation, LOCKMODE lockmode,
|
|
bool missing_ok)
|
|
{
|
|
Oid relOid;
|
|
|
|
/*
|
|
* Check for shared-cache-inval messages before trying to open the
|
|
* relation. See comments in relation_openrv().
|
|
*/
|
|
if (lockmode != NoLock)
|
|
AcceptInvalidationMessages();
|
|
|
|
/* Look up and lock the appropriate relation using namespace search */
|
|
relOid = RangeVarGetRelid(relation, lockmode, missing_ok);
|
|
|
|
/* Return NULL on not-found */
|
|
if (!OidIsValid(relOid))
|
|
return NULL;
|
|
|
|
/* Let relation_open do the rest */
|
|
return relation_open(relOid, NoLock);
|
|
}
|
|
|
|
/* ----------------
|
|
* relation_close - close any relation
|
|
*
|
|
* If lockmode is not "NoLock", we then release the specified lock.
|
|
*
|
|
* Note that it is often sensible to hold a lock beyond relation_close;
|
|
* in that case, the lock is released automatically at xact end.
|
|
* ----------------
|
|
*/
|
|
void
|
|
relation_close(Relation relation, LOCKMODE lockmode)
|
|
{
|
|
LockRelId relid = relation->rd_lockInfo.lockRelId;
|
|
|
|
Assert(lockmode >= NoLock && lockmode < MAX_LOCKMODES);
|
|
|
|
/* The relcache does the real work... */
|
|
RelationClose(relation);
|
|
|
|
if (lockmode != NoLock)
|
|
UnlockRelationId(&relid, lockmode);
|
|
}
|
|
|
|
|
|
/* ----------------
|
|
* heap_open - open a heap relation by relation OID
|
|
*
|
|
* This is essentially relation_open plus check that the relation
|
|
* is not an index nor a composite type. (The caller should also
|
|
* check that it's not a view or foreign table before assuming it has
|
|
* storage.)
|
|
* ----------------
|
|
*/
|
|
Relation
|
|
heap_open(Oid relationId, LOCKMODE lockmode)
|
|
{
|
|
Relation r;
|
|
|
|
r = relation_open(relationId, lockmode);
|
|
|
|
if (r->rd_rel->relkind == RELKIND_INDEX ||
|
|
r->rd_rel->relkind == RELKIND_PARTITIONED_INDEX)
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
|
|
errmsg("\"%s\" is an index",
|
|
RelationGetRelationName(r))));
|
|
else if (r->rd_rel->relkind == RELKIND_COMPOSITE_TYPE)
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
|
|
errmsg("\"%s\" is a composite type",
|
|
RelationGetRelationName(r))));
|
|
|
|
return r;
|
|
}
|
|
|
|
/* ----------------
|
|
* heap_openrv - open a heap relation specified
|
|
* by a RangeVar node
|
|
*
|
|
* As above, but relation is specified by a RangeVar.
|
|
* ----------------
|
|
*/
|
|
Relation
|
|
heap_openrv(const RangeVar *relation, LOCKMODE lockmode)
|
|
{
|
|
Relation r;
|
|
|
|
r = relation_openrv(relation, lockmode);
|
|
|
|
if (r->rd_rel->relkind == RELKIND_INDEX ||
|
|
r->rd_rel->relkind == RELKIND_PARTITIONED_INDEX)
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
|
|
errmsg("\"%s\" is an index",
|
|
RelationGetRelationName(r))));
|
|
else if (r->rd_rel->relkind == RELKIND_COMPOSITE_TYPE)
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
|
|
errmsg("\"%s\" is a composite type",
|
|
RelationGetRelationName(r))));
|
|
|
|
return r;
|
|
}
|
|
|
|
/* ----------------
|
|
* heap_openrv_extended - open a heap relation specified
|
|
* by a RangeVar node
|
|
*
|
|
* As above, but optionally return NULL instead of failing for
|
|
* relation-not-found.
|
|
* ----------------
|
|
*/
|
|
Relation
|
|
heap_openrv_extended(const RangeVar *relation, LOCKMODE lockmode,
|
|
bool missing_ok)
|
|
{
|
|
Relation r;
|
|
|
|
r = relation_openrv_extended(relation, lockmode, missing_ok);
|
|
|
|
if (r)
|
|
{
|
|
if (r->rd_rel->relkind == RELKIND_INDEX ||
|
|
r->rd_rel->relkind == RELKIND_PARTITIONED_INDEX)
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
|
|
errmsg("\"%s\" is an index",
|
|
RelationGetRelationName(r))));
|
|
else if (r->rd_rel->relkind == RELKIND_COMPOSITE_TYPE)
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
|
|
errmsg("\"%s\" is a composite type",
|
|
RelationGetRelationName(r))));
|
|
}
|
|
|
|
return r;
|
|
}
|
|
|
|
|
|
/* ----------------
|
|
* heap_beginscan - begin relation scan
|
|
*
|
|
* heap_beginscan is the "standard" case.
|
|
*
|
|
* heap_beginscan_catalog differs in setting up its own temporary snapshot.
|
|
*
|
|
* heap_beginscan_strat offers an extended API that lets the caller control
|
|
* whether a nondefault buffer access strategy can be used, and whether
|
|
* syncscan can be chosen (possibly resulting in the scan not starting from
|
|
* block zero). Both of these default to true with plain heap_beginscan.
|
|
*
|
|
* heap_beginscan_bm is an alternative entry point for setting up a
|
|
* HeapScanDesc for a bitmap heap scan. Although that scan technology is
|
|
* really quite unlike a standard seqscan, there is just enough commonality
|
|
* to make it worth using the same data structure.
|
|
*
|
|
* heap_beginscan_sampling is an alternative entry point for setting up a
|
|
* HeapScanDesc for a TABLESAMPLE scan. As with bitmap scans, it's worth
|
|
* using the same data structure although the behavior is rather different.
|
|
* In addition to the options offered by heap_beginscan_strat, this call
|
|
* also allows control of whether page-mode visibility checking is used.
|
|
* ----------------
|
|
*/
|
|
HeapScanDesc
|
|
heap_beginscan(Relation relation, Snapshot snapshot,
|
|
int nkeys, ScanKey key)
|
|
{
|
|
return heap_beginscan_internal(relation, snapshot, nkeys, key, NULL,
|
|
true, true, true, false, false, false);
|
|
}
|
|
|
|
HeapScanDesc
|
|
heap_beginscan_catalog(Relation relation, int nkeys, ScanKey key)
|
|
{
|
|
Oid relid = RelationGetRelid(relation);
|
|
Snapshot snapshot = RegisterSnapshot(GetCatalogSnapshot(relid));
|
|
|
|
return heap_beginscan_internal(relation, snapshot, nkeys, key, NULL,
|
|
true, true, true, false, false, true);
|
|
}
|
|
|
|
HeapScanDesc
|
|
heap_beginscan_strat(Relation relation, Snapshot snapshot,
|
|
int nkeys, ScanKey key,
|
|
bool allow_strat, bool allow_sync)
|
|
{
|
|
return heap_beginscan_internal(relation, snapshot, nkeys, key, NULL,
|
|
allow_strat, allow_sync, true,
|
|
false, false, false);
|
|
}
|
|
|
|
HeapScanDesc
|
|
heap_beginscan_bm(Relation relation, Snapshot snapshot,
|
|
int nkeys, ScanKey key)
|
|
{
|
|
return heap_beginscan_internal(relation, snapshot, nkeys, key, NULL,
|
|
false, false, true, true, false, false);
|
|
}
|
|
|
|
HeapScanDesc
|
|
heap_beginscan_sampling(Relation relation, Snapshot snapshot,
|
|
int nkeys, ScanKey key,
|
|
bool allow_strat, bool allow_sync, bool allow_pagemode)
|
|
{
|
|
return heap_beginscan_internal(relation, snapshot, nkeys, key, NULL,
|
|
allow_strat, allow_sync, allow_pagemode,
|
|
false, true, false);
|
|
}
|
|
|
|
static HeapScanDesc
|
|
heap_beginscan_internal(Relation relation, Snapshot snapshot,
|
|
int nkeys, ScanKey key,
|
|
ParallelHeapScanDesc parallel_scan,
|
|
bool allow_strat,
|
|
bool allow_sync,
|
|
bool allow_pagemode,
|
|
bool is_bitmapscan,
|
|
bool is_samplescan,
|
|
bool temp_snap)
|
|
{
|
|
HeapScanDesc scan;
|
|
|
|
/*
|
|
* increment relation ref count while scanning relation
|
|
*
|
|
* This is just to make really sure the relcache entry won't go away while
|
|
* the scan has a pointer to it. Caller should be holding the rel open
|
|
* anyway, so this is redundant in all normal scenarios...
|
|
*/
|
|
RelationIncrementReferenceCount(relation);
|
|
|
|
/*
|
|
* allocate and initialize scan descriptor
|
|
*/
|
|
scan = (HeapScanDesc) palloc(sizeof(HeapScanDescData));
|
|
|
|
scan->rs_rd = relation;
|
|
scan->rs_snapshot = snapshot;
|
|
scan->rs_nkeys = nkeys;
|
|
scan->rs_bitmapscan = is_bitmapscan;
|
|
scan->rs_samplescan = is_samplescan;
|
|
scan->rs_strategy = NULL; /* set in initscan */
|
|
scan->rs_allow_strat = allow_strat;
|
|
scan->rs_allow_sync = allow_sync;
|
|
scan->rs_temp_snap = temp_snap;
|
|
scan->rs_parallel = parallel_scan;
|
|
|
|
/*
|
|
* we can use page-at-a-time mode if it's an MVCC-safe snapshot
|
|
*/
|
|
scan->rs_pageatatime = allow_pagemode && IsMVCCSnapshot(snapshot);
|
|
|
|
/*
|
|
* For a seqscan in a serializable transaction, acquire a predicate lock
|
|
* on the entire relation. This is required not only to lock all the
|
|
* matching tuples, but also to conflict with new insertions into the
|
|
* table. In an indexscan, we take page locks on the index pages covering
|
|
* the range specified in the scan qual, but in a heap scan there is
|
|
* nothing more fine-grained to lock. A bitmap scan is a different story,
|
|
* there we have already scanned the index and locked the index pages
|
|
* covering the predicate. But in that case we still have to lock any
|
|
* matching heap tuples.
|
|
*/
|
|
if (!is_bitmapscan)
|
|
PredicateLockRelation(relation, snapshot);
|
|
|
|
/* we only need to set this up once */
|
|
scan->rs_ctup.t_tableOid = RelationGetRelid(relation);
|
|
|
|
/*
|
|
* we do this here instead of in initscan() because heap_rescan also calls
|
|
* initscan() and we don't want to allocate memory again
|
|
*/
|
|
if (nkeys > 0)
|
|
scan->rs_key = (ScanKey) palloc(sizeof(ScanKeyData) * nkeys);
|
|
else
|
|
scan->rs_key = NULL;
|
|
|
|
initscan(scan, key, false);
|
|
|
|
return scan;
|
|
}
|
|
|
|
/* ----------------
|
|
* heap_rescan - restart a relation scan
|
|
* ----------------
|
|
*/
|
|
void
|
|
heap_rescan(HeapScanDesc scan,
|
|
ScanKey key)
|
|
{
|
|
/*
|
|
* unpin scan buffers
|
|
*/
|
|
if (BufferIsValid(scan->rs_cbuf))
|
|
ReleaseBuffer(scan->rs_cbuf);
|
|
|
|
/*
|
|
* reinitialize scan descriptor
|
|
*/
|
|
initscan(scan, key, true);
|
|
}
|
|
|
|
/* ----------------
|
|
* heap_rescan_set_params - restart a relation scan after changing params
|
|
*
|
|
* This call allows changing the buffer strategy, syncscan, and pagemode
|
|
* options before starting a fresh scan. Note that although the actual use
|
|
* of syncscan might change (effectively, enabling or disabling reporting),
|
|
* the previously selected startblock will be kept.
|
|
* ----------------
|
|
*/
|
|
void
|
|
heap_rescan_set_params(HeapScanDesc scan, ScanKey key,
|
|
bool allow_strat, bool allow_sync, bool allow_pagemode)
|
|
{
|
|
/* adjust parameters */
|
|
scan->rs_allow_strat = allow_strat;
|
|
scan->rs_allow_sync = allow_sync;
|
|
scan->rs_pageatatime = allow_pagemode && IsMVCCSnapshot(scan->rs_snapshot);
|
|
/* ... and rescan */
|
|
heap_rescan(scan, key);
|
|
}
|
|
|
|
/* ----------------
|
|
* heap_endscan - end relation scan
|
|
*
|
|
* See how to integrate with index scans.
|
|
* Check handling if reldesc caching.
|
|
* ----------------
|
|
*/
|
|
void
|
|
heap_endscan(HeapScanDesc scan)
|
|
{
|
|
/* Note: no locking manipulations needed */
|
|
|
|
/*
|
|
* unpin scan buffers
|
|
*/
|
|
if (BufferIsValid(scan->rs_cbuf))
|
|
ReleaseBuffer(scan->rs_cbuf);
|
|
|
|
/*
|
|
* decrement relation reference count and free scan descriptor storage
|
|
*/
|
|
RelationDecrementReferenceCount(scan->rs_rd);
|
|
|
|
if (scan->rs_key)
|
|
pfree(scan->rs_key);
|
|
|
|
if (scan->rs_strategy != NULL)
|
|
FreeAccessStrategy(scan->rs_strategy);
|
|
|
|
if (scan->rs_temp_snap)
|
|
UnregisterSnapshot(scan->rs_snapshot);
|
|
|
|
pfree(scan);
|
|
}
|
|
|
|
/* ----------------
|
|
* heap_parallelscan_estimate - estimate storage for ParallelHeapScanDesc
|
|
*
|
|
* Sadly, this doesn't reduce to a constant, because the size required
|
|
* to serialize the snapshot can vary.
|
|
* ----------------
|
|
*/
|
|
Size
|
|
heap_parallelscan_estimate(Snapshot snapshot)
|
|
{
|
|
return add_size(offsetof(ParallelHeapScanDescData, phs_snapshot_data),
|
|
EstimateSnapshotSpace(snapshot));
|
|
}
|
|
|
|
/* ----------------
|
|
* heap_parallelscan_initialize - initialize ParallelHeapScanDesc
|
|
*
|
|
* Must allow as many bytes of shared memory as returned by
|
|
* heap_parallelscan_estimate. Call this just once in the leader
|
|
* process; then, individual workers attach via heap_beginscan_parallel.
|
|
* ----------------
|
|
*/
|
|
void
|
|
heap_parallelscan_initialize(ParallelHeapScanDesc target, Relation relation,
|
|
Snapshot snapshot)
|
|
{
|
|
target->phs_relid = RelationGetRelid(relation);
|
|
target->phs_nblocks = RelationGetNumberOfBlocks(relation);
|
|
/* compare phs_syncscan initialization to similar logic in initscan */
|
|
target->phs_syncscan = synchronize_seqscans &&
|
|
!RelationUsesLocalBuffers(relation) &&
|
|
target->phs_nblocks > NBuffers / 4;
|
|
SpinLockInit(&target->phs_mutex);
|
|
target->phs_startblock = InvalidBlockNumber;
|
|
pg_atomic_init_u64(&target->phs_nallocated, 0);
|
|
if (IsMVCCSnapshot(snapshot))
|
|
{
|
|
SerializeSnapshot(snapshot, target->phs_snapshot_data);
|
|
target->phs_snapshot_any = false;
|
|
}
|
|
else
|
|
{
|
|
Assert(snapshot == SnapshotAny);
|
|
target->phs_snapshot_any = true;
|
|
}
|
|
}
|
|
|
|
/* ----------------
|
|
* heap_parallelscan_reinitialize - reset a parallel scan
|
|
*
|
|
* Call this in the leader process. Caller is responsible for
|
|
* making sure that all workers have finished the scan beforehand.
|
|
* ----------------
|
|
*/
|
|
void
|
|
heap_parallelscan_reinitialize(ParallelHeapScanDesc parallel_scan)
|
|
{
|
|
pg_atomic_write_u64(¶llel_scan->phs_nallocated, 0);
|
|
}
|
|
|
|
/* ----------------
|
|
* heap_beginscan_parallel - join a parallel scan
|
|
*
|
|
* Caller must hold a suitable lock on the correct relation.
|
|
* ----------------
|
|
*/
|
|
HeapScanDesc
|
|
heap_beginscan_parallel(Relation relation, ParallelHeapScanDesc parallel_scan)
|
|
{
|
|
Snapshot snapshot;
|
|
|
|
Assert(RelationGetRelid(relation) == parallel_scan->phs_relid);
|
|
|
|
if (!parallel_scan->phs_snapshot_any)
|
|
{
|
|
/* Snapshot was serialized -- restore it */
|
|
snapshot = RestoreSnapshot(parallel_scan->phs_snapshot_data);
|
|
RegisterSnapshot(snapshot);
|
|
}
|
|
else
|
|
{
|
|
/* SnapshotAny passed by caller (not serialized) */
|
|
snapshot = SnapshotAny;
|
|
}
|
|
|
|
return heap_beginscan_internal(relation, snapshot, 0, NULL, parallel_scan,
|
|
true, true, true, false, false,
|
|
!parallel_scan->phs_snapshot_any);
|
|
}
|
|
|
|
/* ----------------
|
|
* heap_parallelscan_startblock_init - find and set the scan's startblock
|
|
*
|
|
* Determine where the parallel seq scan should start. This function may
|
|
* be called many times, once by each parallel worker. We must be careful
|
|
* only to set the startblock once.
|
|
* ----------------
|
|
*/
|
|
static void
|
|
heap_parallelscan_startblock_init(HeapScanDesc scan)
|
|
{
|
|
BlockNumber sync_startpage = InvalidBlockNumber;
|
|
ParallelHeapScanDesc parallel_scan;
|
|
|
|
Assert(scan->rs_parallel);
|
|
parallel_scan = scan->rs_parallel;
|
|
|
|
retry:
|
|
/* Grab the spinlock. */
|
|
SpinLockAcquire(¶llel_scan->phs_mutex);
|
|
|
|
/*
|
|
* If the scan's startblock has not yet been initialized, we must do so
|
|
* now. If this is not a synchronized scan, we just start at block 0, but
|
|
* if it is a synchronized scan, we must get the starting position from
|
|
* the synchronized scan machinery. We can't hold the spinlock while
|
|
* doing that, though, so release the spinlock, get the information we
|
|
* need, and retry. If nobody else has initialized the scan in the
|
|
* meantime, we'll fill in the value we fetched on the second time
|
|
* through.
|
|
*/
|
|
if (parallel_scan->phs_startblock == InvalidBlockNumber)
|
|
{
|
|
if (!parallel_scan->phs_syncscan)
|
|
parallel_scan->phs_startblock = 0;
|
|
else if (sync_startpage != InvalidBlockNumber)
|
|
parallel_scan->phs_startblock = sync_startpage;
|
|
else
|
|
{
|
|
SpinLockRelease(¶llel_scan->phs_mutex);
|
|
sync_startpage = ss_get_location(scan->rs_rd, scan->rs_nblocks);
|
|
goto retry;
|
|
}
|
|
}
|
|
SpinLockRelease(¶llel_scan->phs_mutex);
|
|
}
|
|
|
|
/* ----------------
|
|
* heap_parallelscan_nextpage - get the next page to scan
|
|
*
|
|
* Get the next page to scan. Even if there are no pages left to scan,
|
|
* another backend could have grabbed a page to scan and not yet finished
|
|
* looking at it, so it doesn't follow that the scan is done when the
|
|
* first backend gets an InvalidBlockNumber return.
|
|
* ----------------
|
|
*/
|
|
static BlockNumber
|
|
heap_parallelscan_nextpage(HeapScanDesc scan)
|
|
{
|
|
BlockNumber page;
|
|
ParallelHeapScanDesc parallel_scan;
|
|
uint64 nallocated;
|
|
|
|
Assert(scan->rs_parallel);
|
|
parallel_scan = scan->rs_parallel;
|
|
|
|
/*
|
|
* phs_nallocated tracks how many pages have been allocated to workers
|
|
* already. When phs_nallocated >= rs_nblocks, all blocks have been
|
|
* allocated.
|
|
*
|
|
* Because we use an atomic fetch-and-add to fetch the current value, the
|
|
* phs_nallocated counter will exceed rs_nblocks, because workers will
|
|
* still increment the value, when they try to allocate the next block but
|
|
* all blocks have been allocated already. The counter must be 64 bits
|
|
* wide because of that, to avoid wrapping around when rs_nblocks is close
|
|
* to 2^32.
|
|
*
|
|
* The actual page to return is calculated by adding the counter to the
|
|
* starting block number, modulo nblocks.
|
|
*/
|
|
nallocated = pg_atomic_fetch_add_u64(¶llel_scan->phs_nallocated, 1);
|
|
if (nallocated >= scan->rs_nblocks)
|
|
page = InvalidBlockNumber; /* all blocks have been allocated */
|
|
else
|
|
page = (nallocated + parallel_scan->phs_startblock) % scan->rs_nblocks;
|
|
|
|
/*
|
|
* Report scan location. Normally, we report the current page number.
|
|
* When we reach the end of the scan, though, we report the starting page,
|
|
* not the ending page, just so the starting positions for later scans
|
|
* doesn't slew backwards. We only report the position at the end of the
|
|
* scan once, though: subsequent callers will report nothing.
|
|
*/
|
|
if (scan->rs_syncscan)
|
|
{
|
|
if (page != InvalidBlockNumber)
|
|
ss_report_location(scan->rs_rd, page);
|
|
else if (nallocated == scan->rs_nblocks)
|
|
ss_report_location(scan->rs_rd, parallel_scan->phs_startblock);
|
|
}
|
|
|
|
return page;
|
|
}
|
|
|
|
/* ----------------
|
|
* heap_update_snapshot
|
|
*
|
|
* Update snapshot info in heap scan descriptor.
|
|
* ----------------
|
|
*/
|
|
void
|
|
heap_update_snapshot(HeapScanDesc scan, Snapshot snapshot)
|
|
{
|
|
Assert(IsMVCCSnapshot(snapshot));
|
|
|
|
RegisterSnapshot(snapshot);
|
|
scan->rs_snapshot = snapshot;
|
|
scan->rs_temp_snap = true;
|
|
}
|
|
|
|
/* ----------------
|
|
* heap_getnext - retrieve next tuple in scan
|
|
*
|
|
* Fix to work with index relations.
|
|
* We don't return the buffer anymore, but you can get it from the
|
|
* returned HeapTuple.
|
|
* ----------------
|
|
*/
|
|
|
|
#ifdef HEAPDEBUGALL
|
|
#define HEAPDEBUG_1 \
|
|
elog(DEBUG2, "heap_getnext([%s,nkeys=%d],dir=%d) called", \
|
|
RelationGetRelationName(scan->rs_rd), scan->rs_nkeys, (int) direction)
|
|
#define HEAPDEBUG_2 \
|
|
elog(DEBUG2, "heap_getnext returning EOS")
|
|
#define HEAPDEBUG_3 \
|
|
elog(DEBUG2, "heap_getnext returning tuple")
|
|
#else
|
|
#define HEAPDEBUG_1
|
|
#define HEAPDEBUG_2
|
|
#define HEAPDEBUG_3
|
|
#endif /* !defined(HEAPDEBUGALL) */
|
|
|
|
|
|
HeapTuple
|
|
heap_getnext(HeapScanDesc scan, ScanDirection direction)
|
|
{
|
|
/* Note: no locking manipulations needed */
|
|
|
|
HEAPDEBUG_1; /* heap_getnext( info ) */
|
|
|
|
if (scan->rs_pageatatime)
|
|
heapgettup_pagemode(scan, direction,
|
|
scan->rs_nkeys, scan->rs_key);
|
|
else
|
|
heapgettup(scan, direction, scan->rs_nkeys, scan->rs_key);
|
|
|
|
if (scan->rs_ctup.t_data == NULL)
|
|
{
|
|
HEAPDEBUG_2; /* heap_getnext returning EOS */
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* if we get here it means we have a new current scan tuple, so point to
|
|
* the proper return buffer and return the tuple.
|
|
*/
|
|
HEAPDEBUG_3; /* heap_getnext returning tuple */
|
|
|
|
pgstat_count_heap_getnext(scan->rs_rd);
|
|
|
|
return &(scan->rs_ctup);
|
|
}
|
|
|
|
/*
|
|
* heap_fetch - retrieve tuple with given tid
|
|
*
|
|
* On entry, tuple->t_self is the TID to fetch. We pin the buffer holding
|
|
* the tuple, fill in the remaining fields of *tuple, and check the tuple
|
|
* against the specified snapshot.
|
|
*
|
|
* If successful (tuple found and passes snapshot time qual), then *userbuf
|
|
* is set to the buffer holding the tuple and true is returned. The caller
|
|
* must unpin the buffer when done with the tuple.
|
|
*
|
|
* If the tuple is not found (ie, item number references a deleted slot),
|
|
* then tuple->t_data is set to NULL and false is returned.
|
|
*
|
|
* If the tuple is found but fails the time qual check, then false is returned
|
|
* but tuple->t_data is left pointing to the tuple.
|
|
*
|
|
* keep_buf determines what is done with the buffer in the false-result cases.
|
|
* When the caller specifies keep_buf = true, we retain the pin on the buffer
|
|
* and return it in *userbuf (so the caller must eventually unpin it); when
|
|
* keep_buf = false, the pin is released and *userbuf is set to InvalidBuffer.
|
|
*
|
|
* stats_relation is the relation to charge the heap_fetch operation against
|
|
* for statistical purposes. (This could be the heap rel itself, an
|
|
* associated index, or NULL to not count the fetch at all.)
|
|
*
|
|
* heap_fetch does not follow HOT chains: only the exact TID requested will
|
|
* be fetched.
|
|
*
|
|
* It is somewhat inconsistent that we ereport() on invalid block number but
|
|
* return false on invalid item number. There are a couple of reasons though.
|
|
* One is that the caller can relatively easily check the block number for
|
|
* validity, but cannot check the item number without reading the page
|
|
* himself. Another is that when we are following a t_ctid link, we can be
|
|
* reasonably confident that the page number is valid (since VACUUM shouldn't
|
|
* truncate off the destination page without having killed the referencing
|
|
* tuple first), but the item number might well not be good.
|
|
*/
|
|
bool
|
|
heap_fetch(Relation relation,
|
|
Snapshot snapshot,
|
|
HeapTuple tuple,
|
|
Buffer *userbuf,
|
|
bool keep_buf,
|
|
Relation stats_relation)
|
|
{
|
|
ItemPointer tid = &(tuple->t_self);
|
|
ItemId lp;
|
|
Buffer buffer;
|
|
Page page;
|
|
OffsetNumber offnum;
|
|
bool valid;
|
|
|
|
/*
|
|
* Fetch and pin the appropriate page of the relation.
|
|
*/
|
|
buffer = ReadBuffer(relation, ItemPointerGetBlockNumber(tid));
|
|
|
|
/*
|
|
* Need share lock on buffer to examine tuple commit status.
|
|
*/
|
|
LockBuffer(buffer, BUFFER_LOCK_SHARE);
|
|
page = BufferGetPage(buffer);
|
|
TestForOldSnapshot(snapshot, relation, page);
|
|
|
|
/*
|
|
* We'd better check for out-of-range offnum in case of VACUUM since the
|
|
* TID was obtained.
|
|
*/
|
|
offnum = ItemPointerGetOffsetNumber(tid);
|
|
if (offnum < FirstOffsetNumber || offnum > PageGetMaxOffsetNumber(page))
|
|
{
|
|
LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
|
|
if (keep_buf)
|
|
*userbuf = buffer;
|
|
else
|
|
{
|
|
ReleaseBuffer(buffer);
|
|
*userbuf = InvalidBuffer;
|
|
}
|
|
tuple->t_data = NULL;
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* get the item line pointer corresponding to the requested tid
|
|
*/
|
|
lp = PageGetItemId(page, offnum);
|
|
|
|
/*
|
|
* Must check for deleted tuple.
|
|
*/
|
|
if (!ItemIdIsNormal(lp))
|
|
{
|
|
LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
|
|
if (keep_buf)
|
|
*userbuf = buffer;
|
|
else
|
|
{
|
|
ReleaseBuffer(buffer);
|
|
*userbuf = InvalidBuffer;
|
|
}
|
|
tuple->t_data = NULL;
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* fill in *tuple fields
|
|
*/
|
|
tuple->t_data = (HeapTupleHeader) PageGetItem(page, lp);
|
|
tuple->t_len = ItemIdGetLength(lp);
|
|
tuple->t_tableOid = RelationGetRelid(relation);
|
|
|
|
/*
|
|
* check time qualification of tuple, then release lock
|
|
*/
|
|
valid = HeapTupleSatisfiesVisibility(tuple, snapshot, buffer);
|
|
|
|
if (valid)
|
|
PredicateLockTuple(relation, tuple, snapshot);
|
|
|
|
CheckForSerializableConflictOut(valid, relation, tuple, buffer, snapshot);
|
|
|
|
LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
|
|
|
|
if (valid)
|
|
{
|
|
/*
|
|
* All checks passed, so return the tuple as valid. Caller is now
|
|
* responsible for releasing the buffer.
|
|
*/
|
|
*userbuf = buffer;
|
|
|
|
/* Count the successful fetch against appropriate rel, if any */
|
|
if (stats_relation != NULL)
|
|
pgstat_count_heap_fetch(stats_relation);
|
|
|
|
return true;
|
|
}
|
|
|
|
/* Tuple failed time qual, but maybe caller wants to see it anyway. */
|
|
if (keep_buf)
|
|
*userbuf = buffer;
|
|
else
|
|
{
|
|
ReleaseBuffer(buffer);
|
|
*userbuf = InvalidBuffer;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* heap_hot_search_buffer - search HOT chain for tuple satisfying snapshot
|
|
*
|
|
* On entry, *tid is the TID of a tuple (either a simple tuple, or the root
|
|
* of a HOT chain), and buffer is the buffer holding this tuple. We search
|
|
* for the first chain member satisfying the given snapshot. If one is
|
|
* found, we update *tid to reference that tuple's offset number, and
|
|
* return true. If no match, return false without modifying *tid.
|
|
*
|
|
* heapTuple is a caller-supplied buffer. When a match is found, we return
|
|
* the tuple here, in addition to updating *tid. If no match is found, the
|
|
* contents of this buffer on return are undefined.
|
|
*
|
|
* If all_dead is not NULL, we check non-visible tuples to see if they are
|
|
* globally dead; *all_dead is set true if all members of the HOT chain
|
|
* are vacuumable, false if not.
|
|
*
|
|
* Unlike heap_fetch, the caller must already have pin and (at least) share
|
|
* lock on the buffer; it is still pinned/locked at exit. Also unlike
|
|
* heap_fetch, we do not report any pgstats count; caller may do so if wanted.
|
|
*/
|
|
bool
|
|
heap_hot_search_buffer(ItemPointer tid, Relation relation, Buffer buffer,
|
|
Snapshot snapshot, HeapTuple heapTuple,
|
|
bool *all_dead, bool first_call)
|
|
{
|
|
Page dp = (Page) BufferGetPage(buffer);
|
|
TransactionId prev_xmax = InvalidTransactionId;
|
|
OffsetNumber offnum;
|
|
bool at_chain_start;
|
|
bool valid;
|
|
bool skip;
|
|
|
|
/* If this is not the first call, previous call returned a (live!) tuple */
|
|
if (all_dead)
|
|
*all_dead = first_call;
|
|
|
|
Assert(TransactionIdIsValid(RecentGlobalXmin));
|
|
|
|
Assert(ItemPointerGetBlockNumber(tid) == BufferGetBlockNumber(buffer));
|
|
offnum = ItemPointerGetOffsetNumber(tid);
|
|
at_chain_start = first_call;
|
|
skip = !first_call;
|
|
|
|
heapTuple->t_self = *tid;
|
|
|
|
/* Scan through possible multiple members of HOT-chain */
|
|
for (;;)
|
|
{
|
|
ItemId lp;
|
|
|
|
/* check for bogus TID */
|
|
if (offnum < FirstOffsetNumber || offnum > PageGetMaxOffsetNumber(dp))
|
|
break;
|
|
|
|
lp = PageGetItemId(dp, offnum);
|
|
|
|
/* check for unused, dead, or redirected items */
|
|
if (!ItemIdIsNormal(lp))
|
|
{
|
|
/* We should only see a redirect at start of chain */
|
|
if (ItemIdIsRedirected(lp) && at_chain_start)
|
|
{
|
|
/* Follow the redirect */
|
|
offnum = ItemIdGetRedirect(lp);
|
|
at_chain_start = false;
|
|
continue;
|
|
}
|
|
/* else must be end of chain */
|
|
break;
|
|
}
|
|
|
|
heapTuple->t_data = (HeapTupleHeader) PageGetItem(dp, lp);
|
|
heapTuple->t_len = ItemIdGetLength(lp);
|
|
heapTuple->t_tableOid = RelationGetRelid(relation);
|
|
ItemPointerSetOffsetNumber(&heapTuple->t_self, offnum);
|
|
|
|
/*
|
|
* Shouldn't see a HEAP_ONLY tuple at chain start.
|
|
*/
|
|
if (at_chain_start && HeapTupleIsHeapOnly(heapTuple))
|
|
break;
|
|
|
|
/*
|
|
* The xmin should match the previous xmax value, else chain is
|
|
* broken.
|
|
*/
|
|
if (TransactionIdIsValid(prev_xmax) &&
|
|
!TransactionIdEquals(prev_xmax,
|
|
HeapTupleHeaderGetXmin(heapTuple->t_data)))
|
|
break;
|
|
|
|
/*
|
|
* When first_call is true (and thus, skip is initially false) we'll
|
|
* return the first tuple we find. But on later passes, heapTuple
|
|
* will initially be pointing to the tuple we returned last time.
|
|
* Returning it again would be incorrect (and would loop forever), so
|
|
* we skip it and return the next match we find.
|
|
*/
|
|
if (!skip)
|
|
{
|
|
/*
|
|
* For the benefit of logical decoding, have t_self point at the
|
|
* element of the HOT chain we're currently investigating instead
|
|
* of the root tuple of the HOT chain. This is important because
|
|
* the *Satisfies routine for historical mvcc snapshots needs the
|
|
* correct tid to decide about the visibility in some cases.
|
|
*/
|
|
ItemPointerSet(&(heapTuple->t_self), BufferGetBlockNumber(buffer), offnum);
|
|
|
|
/* If it's visible per the snapshot, we must return it */
|
|
valid = HeapTupleSatisfiesVisibility(heapTuple, snapshot, buffer);
|
|
CheckForSerializableConflictOut(valid, relation, heapTuple,
|
|
buffer, snapshot);
|
|
/* reset to original, non-redirected, tid */
|
|
heapTuple->t_self = *tid;
|
|
|
|
if (valid)
|
|
{
|
|
ItemPointerSetOffsetNumber(tid, offnum);
|
|
PredicateLockTuple(relation, heapTuple, snapshot);
|
|
if (all_dead)
|
|
*all_dead = false;
|
|
return true;
|
|
}
|
|
}
|
|
skip = false;
|
|
|
|
/*
|
|
* If we can't see it, maybe no one else can either. At caller
|
|
* request, check whether all chain members are dead to all
|
|
* transactions.
|
|
*
|
|
* Note: if you change the criterion here for what is "dead", fix the
|
|
* planner's get_actual_variable_range() function to match.
|
|
*/
|
|
if (all_dead && *all_dead &&
|
|
!HeapTupleIsSurelyDead(heapTuple, RecentGlobalXmin))
|
|
*all_dead = false;
|
|
|
|
/*
|
|
* Check to see if HOT chain continues past this tuple; if so fetch
|
|
* the next offnum and loop around.
|
|
*/
|
|
if (HeapTupleIsHotUpdated(heapTuple))
|
|
{
|
|
Assert(ItemPointerGetBlockNumber(&heapTuple->t_data->t_ctid) ==
|
|
ItemPointerGetBlockNumber(tid));
|
|
offnum = ItemPointerGetOffsetNumber(&heapTuple->t_data->t_ctid);
|
|
at_chain_start = false;
|
|
prev_xmax = HeapTupleHeaderGetUpdateXid(heapTuple->t_data);
|
|
}
|
|
else
|
|
break; /* end of chain */
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* heap_hot_search - search HOT chain for tuple satisfying snapshot
|
|
*
|
|
* This has the same API as heap_hot_search_buffer, except that the caller
|
|
* does not provide the buffer containing the page, rather we access it
|
|
* locally.
|
|
*/
|
|
bool
|
|
heap_hot_search(ItemPointer tid, Relation relation, Snapshot snapshot,
|
|
bool *all_dead)
|
|
{
|
|
bool result;
|
|
Buffer buffer;
|
|
HeapTupleData heapTuple;
|
|
|
|
buffer = ReadBuffer(relation, ItemPointerGetBlockNumber(tid));
|
|
LockBuffer(buffer, BUFFER_LOCK_SHARE);
|
|
result = heap_hot_search_buffer(tid, relation, buffer, snapshot,
|
|
&heapTuple, all_dead, true);
|
|
LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
|
|
ReleaseBuffer(buffer);
|
|
return result;
|
|
}
|
|
|
|
/*
|
|
* heap_get_latest_tid - get the latest tid of a specified tuple
|
|
*
|
|
* Actually, this gets the latest version that is visible according to
|
|
* the passed snapshot. You can pass SnapshotDirty to get the very latest,
|
|
* possibly uncommitted version.
|
|
*
|
|
* *tid is both an input and an output parameter: it is updated to
|
|
* show the latest version of the row. Note that it will not be changed
|
|
* if no version of the row passes the snapshot test.
|
|
*/
|
|
void
|
|
heap_get_latest_tid(Relation relation,
|
|
Snapshot snapshot,
|
|
ItemPointer tid)
|
|
{
|
|
BlockNumber blk;
|
|
ItemPointerData ctid;
|
|
TransactionId priorXmax;
|
|
|
|
/* this is to avoid Assert failures on bad input */
|
|
if (!ItemPointerIsValid(tid))
|
|
return;
|
|
|
|
/*
|
|
* Since this can be called with user-supplied TID, don't trust the input
|
|
* too much. (RelationGetNumberOfBlocks is an expensive check, so we
|
|
* don't check t_ctid links again this way. Note that it would not do to
|
|
* call it just once and save the result, either.)
|
|
*/
|
|
blk = ItemPointerGetBlockNumber(tid);
|
|
if (blk >= RelationGetNumberOfBlocks(relation))
|
|
elog(ERROR, "block number %u is out of range for relation \"%s\"",
|
|
blk, RelationGetRelationName(relation));
|
|
|
|
/*
|
|
* Loop to chase down t_ctid links. At top of loop, ctid is the tuple we
|
|
* need to examine, and *tid is the TID we will return if ctid turns out
|
|
* to be bogus.
|
|
*
|
|
* Note that we will loop until we reach the end of the t_ctid chain.
|
|
* Depending on the snapshot passed, there might be at most one visible
|
|
* version of the row, but we don't try to optimize for that.
|
|
*/
|
|
ctid = *tid;
|
|
priorXmax = InvalidTransactionId; /* cannot check first XMIN */
|
|
for (;;)
|
|
{
|
|
Buffer buffer;
|
|
Page page;
|
|
OffsetNumber offnum;
|
|
ItemId lp;
|
|
HeapTupleData tp;
|
|
bool valid;
|
|
|
|
/*
|
|
* Read, pin, and lock the page.
|
|
*/
|
|
buffer = ReadBuffer(relation, ItemPointerGetBlockNumber(&ctid));
|
|
LockBuffer(buffer, BUFFER_LOCK_SHARE);
|
|
page = BufferGetPage(buffer);
|
|
TestForOldSnapshot(snapshot, relation, page);
|
|
|
|
/*
|
|
* Check for bogus item number. This is not treated as an error
|
|
* condition because it can happen while following a t_ctid link. We
|
|
* just assume that the prior tid is OK and return it unchanged.
|
|
*/
|
|
offnum = ItemPointerGetOffsetNumber(&ctid);
|
|
if (offnum < FirstOffsetNumber || offnum > PageGetMaxOffsetNumber(page))
|
|
{
|
|
UnlockReleaseBuffer(buffer);
|
|
break;
|
|
}
|
|
lp = PageGetItemId(page, offnum);
|
|
if (!ItemIdIsNormal(lp))
|
|
{
|
|
UnlockReleaseBuffer(buffer);
|
|
break;
|
|
}
|
|
|
|
/* OK to access the tuple */
|
|
tp.t_self = ctid;
|
|
tp.t_data = (HeapTupleHeader) PageGetItem(page, lp);
|
|
tp.t_len = ItemIdGetLength(lp);
|
|
tp.t_tableOid = RelationGetRelid(relation);
|
|
|
|
/*
|
|
* After following a t_ctid link, we might arrive at an unrelated
|
|
* tuple. Check for XMIN match.
|
|
*/
|
|
if (TransactionIdIsValid(priorXmax) &&
|
|
!TransactionIdEquals(priorXmax, HeapTupleHeaderGetXmin(tp.t_data)))
|
|
{
|
|
UnlockReleaseBuffer(buffer);
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* Check time qualification of tuple; if visible, set it as the new
|
|
* result candidate.
|
|
*/
|
|
valid = HeapTupleSatisfiesVisibility(&tp, snapshot, buffer);
|
|
CheckForSerializableConflictOut(valid, relation, &tp, buffer, snapshot);
|
|
if (valid)
|
|
*tid = ctid;
|
|
|
|
/*
|
|
* If there's a valid t_ctid link, follow it, else we're done.
|
|
*/
|
|
if ((tp.t_data->t_infomask & HEAP_XMAX_INVALID) ||
|
|
HeapTupleHeaderIsOnlyLocked(tp.t_data) ||
|
|
ItemPointerEquals(&tp.t_self, &tp.t_data->t_ctid))
|
|
{
|
|
UnlockReleaseBuffer(buffer);
|
|
break;
|
|
}
|
|
|
|
ctid = tp.t_data->t_ctid;
|
|
priorXmax = HeapTupleHeaderGetUpdateXid(tp.t_data);
|
|
UnlockReleaseBuffer(buffer);
|
|
} /* end of loop */
|
|
}
|
|
|
|
|
|
/*
|
|
* UpdateXmaxHintBits - update tuple hint bits after xmax transaction ends
|
|
*
|
|
* This is called after we have waited for the XMAX transaction to terminate.
|
|
* If the transaction aborted, we guarantee the XMAX_INVALID hint bit will
|
|
* be set on exit. If the transaction committed, we set the XMAX_COMMITTED
|
|
* hint bit if possible --- but beware that that may not yet be possible,
|
|
* if the transaction committed asynchronously.
|
|
*
|
|
* Note that if the transaction was a locker only, we set HEAP_XMAX_INVALID
|
|
* even if it commits.
|
|
*
|
|
* Hence callers should look only at XMAX_INVALID.
|
|
*
|
|
* Note this is not allowed for tuples whose xmax is a multixact.
|
|
*/
|
|
static void
|
|
UpdateXmaxHintBits(HeapTupleHeader tuple, Buffer buffer, TransactionId xid)
|
|
{
|
|
Assert(TransactionIdEquals(HeapTupleHeaderGetRawXmax(tuple), xid));
|
|
Assert(!(tuple->t_infomask & HEAP_XMAX_IS_MULTI));
|
|
|
|
if (!(tuple->t_infomask & (HEAP_XMAX_COMMITTED | HEAP_XMAX_INVALID)))
|
|
{
|
|
if (!HEAP_XMAX_IS_LOCKED_ONLY(tuple->t_infomask) &&
|
|
TransactionIdDidCommit(xid))
|
|
HeapTupleSetHintBits(tuple, buffer, HEAP_XMAX_COMMITTED,
|
|
xid);
|
|
else
|
|
HeapTupleSetHintBits(tuple, buffer, HEAP_XMAX_INVALID,
|
|
InvalidTransactionId);
|
|
}
|
|
}
|
|
|
|
|
|
/*
|
|
* GetBulkInsertState - prepare status object for a bulk insert
|
|
*/
|
|
BulkInsertState
|
|
GetBulkInsertState(void)
|
|
{
|
|
BulkInsertState bistate;
|
|
|
|
bistate = (BulkInsertState) palloc(sizeof(BulkInsertStateData));
|
|
bistate->strategy = GetAccessStrategy(BAS_BULKWRITE);
|
|
bistate->current_buf = InvalidBuffer;
|
|
return bistate;
|
|
}
|
|
|
|
/*
|
|
* FreeBulkInsertState - clean up after finishing a bulk insert
|
|
*/
|
|
void
|
|
FreeBulkInsertState(BulkInsertState bistate)
|
|
{
|
|
if (bistate->current_buf != InvalidBuffer)
|
|
ReleaseBuffer(bistate->current_buf);
|
|
FreeAccessStrategy(bistate->strategy);
|
|
pfree(bistate);
|
|
}
|
|
|
|
/*
|
|
* ReleaseBulkInsertStatePin - release a buffer currently held in bistate
|
|
*/
|
|
void
|
|
ReleaseBulkInsertStatePin(BulkInsertState bistate)
|
|
{
|
|
if (bistate->current_buf != InvalidBuffer)
|
|
ReleaseBuffer(bistate->current_buf);
|
|
bistate->current_buf = InvalidBuffer;
|
|
}
|
|
|
|
|
|
/*
|
|
* heap_insert - insert tuple into a heap
|
|
*
|
|
* The new tuple is stamped with current transaction ID and the specified
|
|
* command ID.
|
|
*
|
|
* If the HEAP_INSERT_SKIP_WAL option is specified, the new tuple is not
|
|
* logged in WAL, even for a non-temp relation. Safe usage of this behavior
|
|
* requires that we arrange that all new tuples go into new pages not
|
|
* containing any tuples from other transactions, and that the relation gets
|
|
* fsync'd before commit. (See also heap_sync() comments)
|
|
*
|
|
* The HEAP_INSERT_SKIP_FSM option is passed directly to
|
|
* RelationGetBufferForTuple, which see for more info.
|
|
*
|
|
* HEAP_INSERT_FROZEN should only be specified for inserts into
|
|
* relfilenodes created during the current subtransaction and when
|
|
* there are no prior snapshots or pre-existing portals open.
|
|
* This causes rows to be frozen, which is an MVCC violation and
|
|
* requires explicit options chosen by user.
|
|
*
|
|
* HEAP_INSERT_IS_SPECULATIVE is used on so-called "speculative insertions",
|
|
* which can be backed out afterwards without aborting the whole transaction.
|
|
* Other sessions can wait for the speculative insertion to be confirmed,
|
|
* turning it into a regular tuple, or aborted, as if it never existed.
|
|
* Speculatively inserted tuples behave as "value locks" of short duration,
|
|
* used to implement INSERT .. ON CONFLICT.
|
|
*
|
|
* Note that most of these options will be applied when inserting into the
|
|
* heap's TOAST table, too, if the tuple requires any out-of-line data. Only
|
|
* HEAP_INSERT_IS_SPECULATIVE is explicitly ignored, as the toast data does
|
|
* not partake in speculative insertion.
|
|
*
|
|
* The BulkInsertState object (if any; bistate can be NULL for default
|
|
* behavior) is also just passed through to RelationGetBufferForTuple.
|
|
*
|
|
* The return value is the OID assigned to the tuple (either here or by the
|
|
* caller), or InvalidOid if no OID. The header fields of *tup are updated
|
|
* to match the stored tuple; in particular tup->t_self receives the actual
|
|
* TID where the tuple was stored. But note that any toasting of fields
|
|
* within the tuple data is NOT reflected into *tup.
|
|
*/
|
|
Oid
|
|
heap_insert(Relation relation, HeapTuple tup, CommandId cid,
|
|
int options, BulkInsertState bistate)
|
|
{
|
|
TransactionId xid = GetCurrentTransactionId();
|
|
HeapTuple heaptup;
|
|
Buffer buffer;
|
|
Buffer vmbuffer = InvalidBuffer;
|
|
bool all_visible_cleared = false;
|
|
|
|
/*
|
|
* Fill in tuple header fields, assign an OID, and toast the tuple if
|
|
* necessary.
|
|
*
|
|
* Note: below this point, heaptup is the data we actually intend to store
|
|
* into the relation; tup is the caller's original untoasted data.
|
|
*/
|
|
heaptup = heap_prepare_insert(relation, tup, xid, cid, options);
|
|
|
|
/*
|
|
* Find buffer to insert this tuple into. If the page is all visible,
|
|
* this will also pin the requisite visibility map page.
|
|
*/
|
|
buffer = RelationGetBufferForTuple(relation, heaptup->t_len,
|
|
InvalidBuffer, options, bistate,
|
|
&vmbuffer, NULL);
|
|
|
|
/*
|
|
* We're about to do the actual insert -- but check for conflict first, to
|
|
* avoid possibly having to roll back work we've just done.
|
|
*
|
|
* This is safe without a recheck as long as there is no possibility of
|
|
* another process scanning the page between this check and the insert
|
|
* being visible to the scan (i.e., an exclusive buffer content lock is
|
|
* continuously held from this point until the tuple insert is visible).
|
|
*
|
|
* For a heap insert, we only need to check for table-level SSI locks. Our
|
|
* new tuple can't possibly conflict with existing tuple locks, and heap
|
|
* page locks are only consolidated versions of tuple locks; they do not
|
|
* lock "gaps" as index page locks do. So we don't need to specify a
|
|
* buffer when making the call, which makes for a faster check.
|
|
*/
|
|
CheckForSerializableConflictIn(relation, NULL, InvalidBuffer);
|
|
|
|
/* NO EREPORT(ERROR) from here till changes are logged */
|
|
START_CRIT_SECTION();
|
|
|
|
RelationPutHeapTuple(relation, buffer, heaptup,
|
|
(options & HEAP_INSERT_SPECULATIVE) != 0);
|
|
|
|
if (PageIsAllVisible(BufferGetPage(buffer)))
|
|
{
|
|
all_visible_cleared = true;
|
|
PageClearAllVisible(BufferGetPage(buffer));
|
|
visibilitymap_clear(relation,
|
|
ItemPointerGetBlockNumber(&(heaptup->t_self)),
|
|
vmbuffer, VISIBILITYMAP_VALID_BITS);
|
|
}
|
|
|
|
/*
|
|
* XXX Should we set PageSetPrunable on this page ?
|
|
*
|
|
* The inserting transaction may eventually abort thus making this tuple
|
|
* DEAD and hence available for pruning. Though we don't want to optimize
|
|
* for aborts, if no other tuple in this page is UPDATEd/DELETEd, the
|
|
* aborted tuple will never be pruned until next vacuum is triggered.
|
|
*
|
|
* If you do add PageSetPrunable here, add it in heap_xlog_insert too.
|
|
*/
|
|
|
|
MarkBufferDirty(buffer);
|
|
|
|
/* XLOG stuff */
|
|
if (!(options & HEAP_INSERT_SKIP_WAL) && RelationNeedsWAL(relation))
|
|
{
|
|
xl_heap_insert xlrec;
|
|
xl_heap_header xlhdr;
|
|
XLogRecPtr recptr;
|
|
Page page = BufferGetPage(buffer);
|
|
uint8 info = XLOG_HEAP_INSERT;
|
|
int bufflags = 0;
|
|
|
|
/*
|
|
* If this is a catalog, we need to transmit combocids to properly
|
|
* decode, so log that as well.
|
|
*/
|
|
if (RelationIsAccessibleInLogicalDecoding(relation))
|
|
log_heap_new_cid(relation, heaptup);
|
|
|
|
/*
|
|
* If this is the single and first tuple on page, we can reinit the
|
|
* page instead of restoring the whole thing. Set flag, and hide
|
|
* buffer references from XLogInsert.
|
|
*/
|
|
if (ItemPointerGetOffsetNumber(&(heaptup->t_self)) == FirstOffsetNumber &&
|
|
PageGetMaxOffsetNumber(page) == FirstOffsetNumber)
|
|
{
|
|
info |= XLOG_HEAP_INIT_PAGE;
|
|
bufflags |= REGBUF_WILL_INIT;
|
|
}
|
|
|
|
xlrec.offnum = ItemPointerGetOffsetNumber(&heaptup->t_self);
|
|
xlrec.flags = 0;
|
|
if (all_visible_cleared)
|
|
xlrec.flags |= XLH_INSERT_ALL_VISIBLE_CLEARED;
|
|
if (options & HEAP_INSERT_SPECULATIVE)
|
|
xlrec.flags |= XLH_INSERT_IS_SPECULATIVE;
|
|
Assert(ItemPointerGetBlockNumber(&heaptup->t_self) == BufferGetBlockNumber(buffer));
|
|
|
|
/*
|
|
* For logical decoding, we need the tuple even if we're doing a full
|
|
* page write, so make sure it's included even if we take a full-page
|
|
* image. (XXX We could alternatively store a pointer into the FPW).
|
|
*/
|
|
if (RelationIsLogicallyLogged(relation))
|
|
{
|
|
xlrec.flags |= XLH_INSERT_CONTAINS_NEW_TUPLE;
|
|
bufflags |= REGBUF_KEEP_DATA;
|
|
}
|
|
|
|
XLogBeginInsert();
|
|
XLogRegisterData((char *) &xlrec, SizeOfHeapInsert);
|
|
|
|
xlhdr.t_infomask2 = heaptup->t_data->t_infomask2;
|
|
xlhdr.t_infomask = heaptup->t_data->t_infomask;
|
|
xlhdr.t_hoff = heaptup->t_data->t_hoff;
|
|
|
|
/*
|
|
* note we mark xlhdr as belonging to buffer; if XLogInsert decides to
|
|
* write the whole page to the xlog, we don't need to store
|
|
* xl_heap_header in the xlog.
|
|
*/
|
|
XLogRegisterBuffer(0, buffer, REGBUF_STANDARD | bufflags);
|
|
XLogRegisterBufData(0, (char *) &xlhdr, SizeOfHeapHeader);
|
|
/* PG73FORMAT: write bitmap [+ padding] [+ oid] + data */
|
|
XLogRegisterBufData(0,
|
|
(char *) heaptup->t_data + SizeofHeapTupleHeader,
|
|
heaptup->t_len - SizeofHeapTupleHeader);
|
|
|
|
/* filtering by origin on a row level is much more efficient */
|
|
XLogSetRecordFlags(XLOG_INCLUDE_ORIGIN);
|
|
|
|
recptr = XLogInsert(RM_HEAP_ID, info);
|
|
|
|
PageSetLSN(page, recptr);
|
|
}
|
|
|
|
END_CRIT_SECTION();
|
|
|
|
UnlockReleaseBuffer(buffer);
|
|
if (vmbuffer != InvalidBuffer)
|
|
ReleaseBuffer(vmbuffer);
|
|
|
|
/*
|
|
* If tuple is cachable, mark it for invalidation from the caches in case
|
|
* we abort. Note it is OK to do this after releasing the buffer, because
|
|
* the heaptup data structure is all in local memory, not in the shared
|
|
* buffer.
|
|
*/
|
|
CacheInvalidateHeapTuple(relation, heaptup, NULL);
|
|
|
|
/* Note: speculative insertions are counted too, even if aborted later */
|
|
pgstat_count_heap_insert(relation, 1);
|
|
|
|
/*
|
|
* If heaptup is a private copy, release it. Don't forget to copy t_self
|
|
* back to the caller's image, too.
|
|
*/
|
|
if (heaptup != tup)
|
|
{
|
|
tup->t_self = heaptup->t_self;
|
|
heap_freetuple(heaptup);
|
|
}
|
|
|
|
return HeapTupleGetOid(tup);
|
|
}
|
|
|
|
/*
|
|
* Subroutine for heap_insert(). Prepares a tuple for insertion. This sets the
|
|
* tuple header fields, assigns an OID, and toasts the tuple if necessary.
|
|
* Returns a toasted version of the tuple if it was toasted, or the original
|
|
* tuple if not. Note that in any case, the header fields are also set in
|
|
* the original tuple.
|
|
*/
|
|
static HeapTuple
|
|
heap_prepare_insert(Relation relation, HeapTuple tup, TransactionId xid,
|
|
CommandId cid, int options)
|
|
{
|
|
/*
|
|
* Parallel operations are required to be strictly read-only in a parallel
|
|
* worker. Parallel inserts are not safe even in the leader in the
|
|
* general case, because group locking means that heavyweight locks for
|
|
* relation extension or GIN page locks will not conflict between members
|
|
* of a lock group, but we don't prohibit that case here because there are
|
|
* useful special cases that we can safely allow, such as CREATE TABLE AS.
|
|
*/
|
|
if (IsParallelWorker())
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_INVALID_TRANSACTION_STATE),
|
|
errmsg("cannot insert tuples in a parallel worker")));
|
|
|
|
if (relation->rd_rel->relhasoids)
|
|
{
|
|
#ifdef NOT_USED
|
|
/* this is redundant with an Assert in HeapTupleSetOid */
|
|
Assert(tup->t_data->t_infomask & HEAP_HASOID);
|
|
#endif
|
|
|
|
/*
|
|
* If the object id of this tuple has already been assigned, trust the
|
|
* caller. There are a couple of ways this can happen. At initial db
|
|
* creation, the backend program sets oids for tuples. When we define
|
|
* an index, we set the oid. Finally, in the future, we may allow
|
|
* users to set their own object ids in order to support a persistent
|
|
* object store (objects need to contain pointers to one another).
|
|
*/
|
|
if (!OidIsValid(HeapTupleGetOid(tup)))
|
|
HeapTupleSetOid(tup, GetNewOid(relation));
|
|
}
|
|
else
|
|
{
|
|
/* check there is not space for an OID */
|
|
Assert(!(tup->t_data->t_infomask & HEAP_HASOID));
|
|
}
|
|
|
|
tup->t_data->t_infomask &= ~(HEAP_XACT_MASK);
|
|
tup->t_data->t_infomask2 &= ~(HEAP2_XACT_MASK);
|
|
tup->t_data->t_infomask |= HEAP_XMAX_INVALID;
|
|
HeapTupleHeaderSetXmin(tup->t_data, xid);
|
|
if (options & HEAP_INSERT_FROZEN)
|
|
HeapTupleHeaderSetXminFrozen(tup->t_data);
|
|
|
|
HeapTupleHeaderSetCmin(tup->t_data, cid);
|
|
HeapTupleHeaderSetXmax(tup->t_data, 0); /* for cleanliness */
|
|
tup->t_tableOid = RelationGetRelid(relation);
|
|
|
|
/*
|
|
* If the new tuple is too big for storage or contains already toasted
|
|
* out-of-line attributes from some other relation, invoke the toaster.
|
|
*/
|
|
if (relation->rd_rel->relkind != RELKIND_RELATION &&
|
|
relation->rd_rel->relkind != RELKIND_MATVIEW)
|
|
{
|
|
/* toast table entries should never be recursively toasted */
|
|
Assert(!HeapTupleHasExternal(tup));
|
|
return tup;
|
|
}
|
|
else if (HeapTupleHasExternal(tup) || tup->t_len > TOAST_TUPLE_THRESHOLD)
|
|
return toast_insert_or_update(relation, tup, NULL, options);
|
|
else
|
|
return tup;
|
|
}
|
|
|
|
/*
|
|
* heap_multi_insert - insert multiple tuple into a heap
|
|
*
|
|
* This is like heap_insert(), but inserts multiple tuples in one operation.
|
|
* That's faster than calling heap_insert() in a loop, because when multiple
|
|
* tuples can be inserted on a single page, we can write just a single WAL
|
|
* record covering all of them, and only need to lock/unlock the page once.
|
|
*
|
|
* Note: this leaks memory into the current memory context. You can create a
|
|
* temporary context before calling this, if that's a problem.
|
|
*/
|
|
void
|
|
heap_multi_insert(Relation relation, HeapTuple *tuples, int ntuples,
|
|
CommandId cid, int options, BulkInsertState bistate)
|
|
{
|
|
TransactionId xid = GetCurrentTransactionId();
|
|
HeapTuple *heaptuples;
|
|
int i;
|
|
int ndone;
|
|
char *scratch = NULL;
|
|
Page page;
|
|
bool needwal;
|
|
Size saveFreeSpace;
|
|
bool need_tuple_data = RelationIsLogicallyLogged(relation);
|
|
bool need_cids = RelationIsAccessibleInLogicalDecoding(relation);
|
|
|
|
needwal = !(options & HEAP_INSERT_SKIP_WAL) && RelationNeedsWAL(relation);
|
|
saveFreeSpace = RelationGetTargetPageFreeSpace(relation,
|
|
HEAP_DEFAULT_FILLFACTOR);
|
|
|
|
/* Toast and set header data in all the tuples */
|
|
heaptuples = palloc(ntuples * sizeof(HeapTuple));
|
|
for (i = 0; i < ntuples; i++)
|
|
heaptuples[i] = heap_prepare_insert(relation, tuples[i],
|
|
xid, cid, options);
|
|
|
|
/*
|
|
* Allocate some memory to use for constructing the WAL record. Using
|
|
* palloc() within a critical section is not safe, so we allocate this
|
|
* beforehand.
|
|
*/
|
|
if (needwal)
|
|
scratch = palloc(BLCKSZ);
|
|
|
|
/*
|
|
* We're about to do the actual inserts -- but check for conflict first,
|
|
* to minimize the possibility of having to roll back work we've just
|
|
* done.
|
|
*
|
|
* A check here does not definitively prevent a serialization anomaly;
|
|
* that check MUST be done at least past the point of acquiring an
|
|
* exclusive buffer content lock on every buffer that will be affected,
|
|
* and MAY be done after all inserts are reflected in the buffers and
|
|
* those locks are released; otherwise there race condition. Since
|
|
* multiple buffers can be locked and unlocked in the loop below, and it
|
|
* would not be feasible to identify and lock all of those buffers before
|
|
* the loop, we must do a final check at the end.
|
|
*
|
|
* The check here could be omitted with no loss of correctness; it is
|
|
* present strictly as an optimization.
|
|
*
|
|
* For heap inserts, we only need to check for table-level SSI locks. Our
|
|
* new tuples can't possibly conflict with existing tuple locks, and heap
|
|
* page locks are only consolidated versions of tuple locks; they do not
|
|
* lock "gaps" as index page locks do. So we don't need to specify a
|
|
* buffer when making the call, which makes for a faster check.
|
|
*/
|
|
CheckForSerializableConflictIn(relation, NULL, InvalidBuffer);
|
|
|
|
ndone = 0;
|
|
while (ndone < ntuples)
|
|
{
|
|
Buffer buffer;
|
|
Buffer vmbuffer = InvalidBuffer;
|
|
bool all_visible_cleared = false;
|
|
int nthispage;
|
|
|
|
CHECK_FOR_INTERRUPTS();
|
|
|
|
/*
|
|
* Find buffer where at least the next tuple will fit. If the page is
|
|
* all-visible, this will also pin the requisite visibility map page.
|
|
*/
|
|
buffer = RelationGetBufferForTuple(relation, heaptuples[ndone]->t_len,
|
|
InvalidBuffer, options, bistate,
|
|
&vmbuffer, NULL);
|
|
page = BufferGetPage(buffer);
|
|
|
|
/* NO EREPORT(ERROR) from here till changes are logged */
|
|
START_CRIT_SECTION();
|
|
|
|
/*
|
|
* RelationGetBufferForTuple has ensured that the first tuple fits.
|
|
* Put that on the page, and then as many other tuples as fit.
|
|
*/
|
|
RelationPutHeapTuple(relation, buffer, heaptuples[ndone], false);
|
|
for (nthispage = 1; ndone + nthispage < ntuples; nthispage++)
|
|
{
|
|
HeapTuple heaptup = heaptuples[ndone + nthispage];
|
|
|
|
if (PageGetHeapFreeSpace(page) < MAXALIGN(heaptup->t_len) + saveFreeSpace)
|
|
break;
|
|
|
|
RelationPutHeapTuple(relation, buffer, heaptup, false);
|
|
|
|
/*
|
|
* We don't use heap_multi_insert for catalog tuples yet, but
|
|
* better be prepared...
|
|
*/
|
|
if (needwal && need_cids)
|
|
log_heap_new_cid(relation, heaptup);
|
|
}
|
|
|
|
if (PageIsAllVisible(page))
|
|
{
|
|
all_visible_cleared = true;
|
|
PageClearAllVisible(page);
|
|
visibilitymap_clear(relation,
|
|
BufferGetBlockNumber(buffer),
|
|
vmbuffer, VISIBILITYMAP_VALID_BITS);
|
|
}
|
|
|
|
/*
|
|
* XXX Should we set PageSetPrunable on this page ? See heap_insert()
|
|
*/
|
|
|
|
MarkBufferDirty(buffer);
|
|
|
|
/* XLOG stuff */
|
|
if (needwal)
|
|
{
|
|
XLogRecPtr recptr;
|
|
xl_heap_multi_insert *xlrec;
|
|
uint8 info = XLOG_HEAP2_MULTI_INSERT;
|
|
char *tupledata;
|
|
int totaldatalen;
|
|
char *scratchptr = scratch;
|
|
bool init;
|
|
int bufflags = 0;
|
|
|
|
/*
|
|
* If the page was previously empty, we can reinit the page
|
|
* instead of restoring the whole thing.
|
|
*/
|
|
init = (ItemPointerGetOffsetNumber(&(heaptuples[ndone]->t_self)) == FirstOffsetNumber &&
|
|
PageGetMaxOffsetNumber(page) == FirstOffsetNumber + nthispage - 1);
|
|
|
|
/* allocate xl_heap_multi_insert struct from the scratch area */
|
|
xlrec = (xl_heap_multi_insert *) scratchptr;
|
|
scratchptr += SizeOfHeapMultiInsert;
|
|
|
|
/*
|
|
* Allocate offsets array. Unless we're reinitializing the page,
|
|
* in that case the tuples are stored in order starting at
|
|
* FirstOffsetNumber and we don't need to store the offsets
|
|
* explicitly.
|
|
*/
|
|
if (!init)
|
|
scratchptr += nthispage * sizeof(OffsetNumber);
|
|
|
|
/* the rest of the scratch space is used for tuple data */
|
|
tupledata = scratchptr;
|
|
|
|
xlrec->flags = all_visible_cleared ? XLH_INSERT_ALL_VISIBLE_CLEARED : 0;
|
|
xlrec->ntuples = nthispage;
|
|
|
|
/*
|
|
* Write out an xl_multi_insert_tuple and the tuple data itself
|
|
* for each tuple.
|
|
*/
|
|
for (i = 0; i < nthispage; i++)
|
|
{
|
|
HeapTuple heaptup = heaptuples[ndone + i];
|
|
xl_multi_insert_tuple *tuphdr;
|
|
int datalen;
|
|
|
|
if (!init)
|
|
xlrec->offsets[i] = ItemPointerGetOffsetNumber(&heaptup->t_self);
|
|
/* xl_multi_insert_tuple needs two-byte alignment. */
|
|
tuphdr = (xl_multi_insert_tuple *) SHORTALIGN(scratchptr);
|
|
scratchptr = ((char *) tuphdr) + SizeOfMultiInsertTuple;
|
|
|
|
tuphdr->t_infomask2 = heaptup->t_data->t_infomask2;
|
|
tuphdr->t_infomask = heaptup->t_data->t_infomask;
|
|
tuphdr->t_hoff = heaptup->t_data->t_hoff;
|
|
|
|
/* write bitmap [+ padding] [+ oid] + data */
|
|
datalen = heaptup->t_len - SizeofHeapTupleHeader;
|
|
memcpy(scratchptr,
|
|
(char *) heaptup->t_data + SizeofHeapTupleHeader,
|
|
datalen);
|
|
tuphdr->datalen = datalen;
|
|
scratchptr += datalen;
|
|
}
|
|
totaldatalen = scratchptr - tupledata;
|
|
Assert((scratchptr - scratch) < BLCKSZ);
|
|
|
|
if (need_tuple_data)
|
|
xlrec->flags |= XLH_INSERT_CONTAINS_NEW_TUPLE;
|
|
|
|
/*
|
|
* Signal that this is the last xl_heap_multi_insert record
|
|
* emitted by this call to heap_multi_insert(). Needed for logical
|
|
* decoding so it knows when to cleanup temporary data.
|
|
*/
|
|
if (ndone + nthispage == ntuples)
|
|
xlrec->flags |= XLH_INSERT_LAST_IN_MULTI;
|
|
|
|
if (init)
|
|
{
|
|
info |= XLOG_HEAP_INIT_PAGE;
|
|
bufflags |= REGBUF_WILL_INIT;
|
|
}
|
|
|
|
/*
|
|
* If we're doing logical decoding, include the new tuple data
|
|
* even if we take a full-page image of the page.
|
|
*/
|
|
if (need_tuple_data)
|
|
bufflags |= REGBUF_KEEP_DATA;
|
|
|
|
XLogBeginInsert();
|
|
XLogRegisterData((char *) xlrec, tupledata - scratch);
|
|
XLogRegisterBuffer(0, buffer, REGBUF_STANDARD | bufflags);
|
|
|
|
XLogRegisterBufData(0, tupledata, totaldatalen);
|
|
|
|
/* filtering by origin on a row level is much more efficient */
|
|
XLogSetRecordFlags(XLOG_INCLUDE_ORIGIN);
|
|
|
|
recptr = XLogInsert(RM_HEAP2_ID, info);
|
|
|
|
PageSetLSN(page, recptr);
|
|
}
|
|
|
|
END_CRIT_SECTION();
|
|
|
|
UnlockReleaseBuffer(buffer);
|
|
if (vmbuffer != InvalidBuffer)
|
|
ReleaseBuffer(vmbuffer);
|
|
|
|
ndone += nthispage;
|
|
}
|
|
|
|
/*
|
|
* We're done with the actual inserts. Check for conflicts again, to
|
|
* ensure that all rw-conflicts in to these inserts are detected. Without
|
|
* this final check, a sequential scan of the heap may have locked the
|
|
* table after the "before" check, missing one opportunity to detect the
|
|
* conflict, and then scanned the table before the new tuples were there,
|
|
* missing the other chance to detect the conflict.
|
|
*
|
|
* For heap inserts, we only need to check for table-level SSI locks. Our
|
|
* new tuples can't possibly conflict with existing tuple locks, and heap
|
|
* page locks are only consolidated versions of tuple locks; they do not
|
|
* lock "gaps" as index page locks do. So we don't need to specify a
|
|
* buffer when making the call.
|
|
*/
|
|
CheckForSerializableConflictIn(relation, NULL, InvalidBuffer);
|
|
|
|
/*
|
|
* If tuples are cachable, mark them for invalidation from the caches in
|
|
* case we abort. Note it is OK to do this after releasing the buffer,
|
|
* because the heaptuples data structure is all in local memory, not in
|
|
* the shared buffer.
|
|
*/
|
|
if (IsCatalogRelation(relation))
|
|
{
|
|
for (i = 0; i < ntuples; i++)
|
|
CacheInvalidateHeapTuple(relation, heaptuples[i], NULL);
|
|
}
|
|
|
|
/*
|
|
* Copy t_self fields back to the caller's original tuples. This does
|
|
* nothing for untoasted tuples (tuples[i] == heaptuples[i)], but it's
|
|
* probably faster to always copy than check.
|
|
*/
|
|
for (i = 0; i < ntuples; i++)
|
|
tuples[i]->t_self = heaptuples[i]->t_self;
|
|
|
|
pgstat_count_heap_insert(relation, ntuples);
|
|
}
|
|
|
|
/*
|
|
* simple_heap_insert - insert a tuple
|
|
*
|
|
* Currently, this routine differs from heap_insert only in supplying
|
|
* a default command ID and not allowing access to the speedup options.
|
|
*
|
|
* This should be used rather than using heap_insert directly in most places
|
|
* where we are modifying system catalogs.
|
|
*/
|
|
Oid
|
|
simple_heap_insert(Relation relation, HeapTuple tup)
|
|
{
|
|
return heap_insert(relation, tup, GetCurrentCommandId(true), 0, NULL);
|
|
}
|
|
|
|
/*
|
|
* Given infomask/infomask2, compute the bits that must be saved in the
|
|
* "infobits" field of xl_heap_delete, xl_heap_update, xl_heap_lock,
|
|
* xl_heap_lock_updated WAL records.
|
|
*
|
|
* See fix_infomask_from_infobits.
|
|
*/
|
|
static uint8
|
|
compute_infobits(uint16 infomask, uint16 infomask2)
|
|
{
|
|
return
|
|
((infomask & HEAP_XMAX_IS_MULTI) != 0 ? XLHL_XMAX_IS_MULTI : 0) |
|
|
((infomask & HEAP_XMAX_LOCK_ONLY) != 0 ? XLHL_XMAX_LOCK_ONLY : 0) |
|
|
((infomask & HEAP_XMAX_EXCL_LOCK) != 0 ? XLHL_XMAX_EXCL_LOCK : 0) |
|
|
/* note we ignore HEAP_XMAX_SHR_LOCK here */
|
|
((infomask & HEAP_XMAX_KEYSHR_LOCK) != 0 ? XLHL_XMAX_KEYSHR_LOCK : 0) |
|
|
((infomask2 & HEAP_KEYS_UPDATED) != 0 ?
|
|
XLHL_KEYS_UPDATED : 0);
|
|
}
|
|
|
|
/*
|
|
* Given two versions of the same t_infomask for a tuple, compare them and
|
|
* return whether the relevant status for a tuple Xmax has changed. This is
|
|
* used after a buffer lock has been released and reacquired: we want to ensure
|
|
* that the tuple state continues to be the same it was when we previously
|
|
* examined it.
|
|
*
|
|
* Note the Xmax field itself must be compared separately.
|
|
*/
|
|
static inline bool
|
|
xmax_infomask_changed(uint16 new_infomask, uint16 old_infomask)
|
|
{
|
|
const uint16 interesting =
|
|
HEAP_XMAX_IS_MULTI | HEAP_XMAX_LOCK_ONLY | HEAP_LOCK_MASK;
|
|
|
|
if ((new_infomask & interesting) != (old_infomask & interesting))
|
|
return true;
|
|
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* heap_delete - delete a tuple
|
|
*
|
|
* NB: do not call this directly unless you are prepared to deal with
|
|
* concurrent-update conditions. Use simple_heap_delete instead.
|
|
*
|
|
* relation - table to be modified (caller must hold suitable lock)
|
|
* tid - TID of tuple to be deleted
|
|
* cid - delete command ID (used for visibility test, and stored into
|
|
* cmax if successful)
|
|
* crosscheck - if not InvalidSnapshot, also check tuple against this
|
|
* wait - true if should wait for any conflicting update to commit/abort
|
|
* hufd - output parameter, filled in failure cases (see below)
|
|
*
|
|
* Normal, successful return value is HeapTupleMayBeUpdated, which
|
|
* actually means we did delete it. Failure return codes are
|
|
* HeapTupleSelfUpdated, HeapTupleUpdated, or HeapTupleBeingUpdated
|
|
* (the last only possible if wait == false).
|
|
*
|
|
* In the failure cases, the routine fills *hufd with the tuple's t_ctid,
|
|
* t_xmax (resolving a possible MultiXact, if necessary), and t_cmax
|
|
* (the last only for HeapTupleSelfUpdated, since we
|
|
* cannot obtain cmax from a combocid generated by another transaction).
|
|
* See comments for struct HeapUpdateFailureData for additional info.
|
|
*/
|
|
HTSU_Result
|
|
heap_delete(Relation relation, ItemPointer tid,
|
|
CommandId cid, Snapshot crosscheck, bool wait,
|
|
HeapUpdateFailureData *hufd)
|
|
{
|
|
HTSU_Result result;
|
|
TransactionId xid = GetCurrentTransactionId();
|
|
ItemId lp;
|
|
HeapTupleData tp;
|
|
Page page;
|
|
BlockNumber block;
|
|
Buffer buffer;
|
|
Buffer vmbuffer = InvalidBuffer;
|
|
TransactionId new_xmax;
|
|
uint16 new_infomask,
|
|
new_infomask2;
|
|
bool have_tuple_lock = false;
|
|
bool iscombo;
|
|
bool all_visible_cleared = false;
|
|
HeapTuple old_key_tuple = NULL; /* replica identity of the tuple */
|
|
bool old_key_copied = false;
|
|
|
|
Assert(ItemPointerIsValid(tid));
|
|
|
|
/*
|
|
* Forbid this during a parallel operation, lest it allocate a combocid.
|
|
* Other workers might need that combocid for visibility checks, and we
|
|
* have no provision for broadcasting it to them.
|
|
*/
|
|
if (IsInParallelMode())
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_INVALID_TRANSACTION_STATE),
|
|
errmsg("cannot delete tuples during a parallel operation")));
|
|
|
|
block = ItemPointerGetBlockNumber(tid);
|
|
buffer = ReadBuffer(relation, block);
|
|
page = BufferGetPage(buffer);
|
|
|
|
/*
|
|
* Before locking the buffer, pin the visibility map page if it appears to
|
|
* be necessary. Since we haven't got the lock yet, someone else might be
|
|
* in the middle of changing this, so we'll need to recheck after we have
|
|
* the lock.
|
|
*/
|
|
if (PageIsAllVisible(page))
|
|
visibilitymap_pin(relation, block, &vmbuffer);
|
|
|
|
LockBuffer(buffer, BUFFER_LOCK_EXCLUSIVE);
|
|
|
|
/*
|
|
* If we didn't pin the visibility map page and the page has become all
|
|
* visible while we were busy locking the buffer, we'll have to unlock and
|
|
* re-lock, to avoid holding the buffer lock across an I/O. That's a bit
|
|
* unfortunate, but hopefully shouldn't happen often.
|
|
*/
|
|
if (vmbuffer == InvalidBuffer && PageIsAllVisible(page))
|
|
{
|
|
LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
|
|
visibilitymap_pin(relation, block, &vmbuffer);
|
|
LockBuffer(buffer, BUFFER_LOCK_EXCLUSIVE);
|
|
}
|
|
|
|
lp = PageGetItemId(page, ItemPointerGetOffsetNumber(tid));
|
|
Assert(ItemIdIsNormal(lp));
|
|
|
|
tp.t_tableOid = RelationGetRelid(relation);
|
|
tp.t_data = (HeapTupleHeader) PageGetItem(page, lp);
|
|
tp.t_len = ItemIdGetLength(lp);
|
|
tp.t_self = *tid;
|
|
|
|
l1:
|
|
result = HeapTupleSatisfiesUpdate(&tp, cid, buffer);
|
|
|
|
if (result == HeapTupleInvisible)
|
|
{
|
|
UnlockReleaseBuffer(buffer);
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
|
|
errmsg("attempted to delete invisible tuple")));
|
|
}
|
|
else if (result == HeapTupleBeingUpdated && wait)
|
|
{
|
|
TransactionId xwait;
|
|
uint16 infomask;
|
|
|
|
/* must copy state data before unlocking buffer */
|
|
xwait = HeapTupleHeaderGetRawXmax(tp.t_data);
|
|
infomask = tp.t_data->t_infomask;
|
|
|
|
/*
|
|
* Sleep until concurrent transaction ends -- except when there's a
|
|
* single locker and it's our own transaction. Note we don't care
|
|
* which lock mode the locker has, because we need the strongest one.
|
|
*
|
|
* Before sleeping, we need to acquire tuple lock to establish our
|
|
* priority for the tuple (see heap_lock_tuple). LockTuple will
|
|
* release us when we are next-in-line for the tuple.
|
|
*
|
|
* If we are forced to "start over" below, we keep the tuple lock;
|
|
* this arranges that we stay at the head of the line while rechecking
|
|
* tuple state.
|
|
*/
|
|
if (infomask & HEAP_XMAX_IS_MULTI)
|
|
{
|
|
/* wait for multixact */
|
|
if (DoesMultiXactIdConflict((MultiXactId) xwait, infomask,
|
|
LockTupleExclusive))
|
|
{
|
|
LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
|
|
|
|
/* acquire tuple lock, if necessary */
|
|
heap_acquire_tuplock(relation, &(tp.t_self), LockTupleExclusive,
|
|
LockWaitBlock, &have_tuple_lock);
|
|
|
|
/* wait for multixact */
|
|
MultiXactIdWait((MultiXactId) xwait, MultiXactStatusUpdate, infomask,
|
|
relation, &(tp.t_self), XLTW_Delete,
|
|
NULL);
|
|
LockBuffer(buffer, BUFFER_LOCK_EXCLUSIVE);
|
|
|
|
/*
|
|
* If xwait had just locked the tuple then some other xact
|
|
* could update this tuple before we get to this point. Check
|
|
* for xmax change, and start over if so.
|
|
*/
|
|
if (xmax_infomask_changed(tp.t_data->t_infomask, infomask) ||
|
|
!TransactionIdEquals(HeapTupleHeaderGetRawXmax(tp.t_data),
|
|
xwait))
|
|
goto l1;
|
|
}
|
|
|
|
/*
|
|
* You might think the multixact is necessarily done here, but not
|
|
* so: it could have surviving members, namely our own xact or
|
|
* other subxacts of this backend. It is legal for us to delete
|
|
* the tuple in either case, however (the latter case is
|
|
* essentially a situation of upgrading our former shared lock to
|
|
* exclusive). We don't bother changing the on-disk hint bits
|
|
* since we are about to overwrite the xmax altogether.
|
|
*/
|
|
}
|
|
else if (!TransactionIdIsCurrentTransactionId(xwait))
|
|
{
|
|
/*
|
|
* Wait for regular transaction to end; but first, acquire tuple
|
|
* lock.
|
|
*/
|
|
LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
|
|
heap_acquire_tuplock(relation, &(tp.t_self), LockTupleExclusive,
|
|
LockWaitBlock, &have_tuple_lock);
|
|
XactLockTableWait(xwait, relation, &(tp.t_self), XLTW_Delete);
|
|
LockBuffer(buffer, BUFFER_LOCK_EXCLUSIVE);
|
|
|
|
/*
|
|
* xwait is done, but if xwait had just locked the tuple then some
|
|
* other xact could update this tuple before we get to this point.
|
|
* Check for xmax change, and start over if so.
|
|
*/
|
|
if (xmax_infomask_changed(tp.t_data->t_infomask, infomask) ||
|
|
!TransactionIdEquals(HeapTupleHeaderGetRawXmax(tp.t_data),
|
|
xwait))
|
|
goto l1;
|
|
|
|
/* Otherwise check if it committed or aborted */
|
|
UpdateXmaxHintBits(tp.t_data, buffer, xwait);
|
|
}
|
|
|
|
/*
|
|
* We may overwrite if previous xmax aborted, or if it committed but
|
|
* only locked the tuple without updating it.
|
|
*/
|
|
if ((tp.t_data->t_infomask & HEAP_XMAX_INVALID) ||
|
|
HEAP_XMAX_IS_LOCKED_ONLY(tp.t_data->t_infomask) ||
|
|
HeapTupleHeaderIsOnlyLocked(tp.t_data))
|
|
result = HeapTupleMayBeUpdated;
|
|
else
|
|
result = HeapTupleUpdated;
|
|
}
|
|
|
|
if (crosscheck != InvalidSnapshot && result == HeapTupleMayBeUpdated)
|
|
{
|
|
/* Perform additional check for transaction-snapshot mode RI updates */
|
|
if (!HeapTupleSatisfiesVisibility(&tp, crosscheck, buffer))
|
|
result = HeapTupleUpdated;
|
|
}
|
|
|
|
if (result != HeapTupleMayBeUpdated)
|
|
{
|
|
Assert(result == HeapTupleSelfUpdated ||
|
|
result == HeapTupleUpdated ||
|
|
result == HeapTupleBeingUpdated);
|
|
Assert(!(tp.t_data->t_infomask & HEAP_XMAX_INVALID));
|
|
hufd->ctid = tp.t_data->t_ctid;
|
|
hufd->xmax = HeapTupleHeaderGetUpdateXid(tp.t_data);
|
|
if (result == HeapTupleSelfUpdated)
|
|
hufd->cmax = HeapTupleHeaderGetCmax(tp.t_data);
|
|
else
|
|
hufd->cmax = InvalidCommandId;
|
|
UnlockReleaseBuffer(buffer);
|
|
if (have_tuple_lock)
|
|
UnlockTupleTuplock(relation, &(tp.t_self), LockTupleExclusive);
|
|
if (vmbuffer != InvalidBuffer)
|
|
ReleaseBuffer(vmbuffer);
|
|
return result;
|
|
}
|
|
|
|
/*
|
|
* We're about to do the actual delete -- check for conflict first, to
|
|
* avoid possibly having to roll back work we've just done.
|
|
*
|
|
* This is safe without a recheck as long as there is no possibility of
|
|
* another process scanning the page between this check and the delete
|
|
* being visible to the scan (i.e., an exclusive buffer content lock is
|
|
* continuously held from this point until the tuple delete is visible).
|
|
*/
|
|
CheckForSerializableConflictIn(relation, &tp, buffer);
|
|
|
|
/* replace cid with a combo cid if necessary */
|
|
HeapTupleHeaderAdjustCmax(tp.t_data, &cid, &iscombo);
|
|
|
|
/*
|
|
* Compute replica identity tuple before entering the critical section so
|
|
* we don't PANIC upon a memory allocation failure.
|
|
*/
|
|
old_key_tuple = ExtractReplicaIdentity(relation, &tp, true, &old_key_copied);
|
|
|
|
/*
|
|
* If this is the first possibly-multixact-able operation in the current
|
|
* transaction, set my per-backend OldestMemberMXactId setting. We can be
|
|
* certain that the transaction will never become a member of any older
|
|
* MultiXactIds than that. (We have to do this even if we end up just
|
|
* using our own TransactionId below, since some other backend could
|
|
* incorporate our XID into a MultiXact immediately afterwards.)
|
|
*/
|
|
MultiXactIdSetOldestMember();
|
|
|
|
compute_new_xmax_infomask(HeapTupleHeaderGetRawXmax(tp.t_data),
|
|
tp.t_data->t_infomask, tp.t_data->t_infomask2,
|
|
xid, LockTupleExclusive, true,
|
|
&new_xmax, &new_infomask, &new_infomask2);
|
|
|
|
START_CRIT_SECTION();
|
|
|
|
/*
|
|
* If this transaction commits, the tuple will become DEAD sooner or
|
|
* later. Set flag that this page is a candidate for pruning once our xid
|
|
* falls below the OldestXmin horizon. If the transaction finally aborts,
|
|
* the subsequent page pruning will be a no-op and the hint will be
|
|
* cleared.
|
|
*/
|
|
PageSetPrunable(page, xid);
|
|
|
|
if (PageIsAllVisible(page))
|
|
{
|
|
all_visible_cleared = true;
|
|
PageClearAllVisible(page);
|
|
visibilitymap_clear(relation, BufferGetBlockNumber(buffer),
|
|
vmbuffer, VISIBILITYMAP_VALID_BITS);
|
|
}
|
|
|
|
/* store transaction information of xact deleting the tuple */
|
|
tp.t_data->t_infomask &= ~(HEAP_XMAX_BITS | HEAP_MOVED);
|
|
tp.t_data->t_infomask2 &= ~HEAP_KEYS_UPDATED;
|
|
tp.t_data->t_infomask |= new_infomask;
|
|
tp.t_data->t_infomask2 |= new_infomask2;
|
|
HeapTupleHeaderClearHotUpdated(tp.t_data);
|
|
HeapTupleHeaderSetXmax(tp.t_data, new_xmax);
|
|
HeapTupleHeaderSetCmax(tp.t_data, cid, iscombo);
|
|
/* Make sure there is no forward chain link in t_ctid */
|
|
tp.t_data->t_ctid = tp.t_self;
|
|
|
|
MarkBufferDirty(buffer);
|
|
|
|
/*
|
|
* XLOG stuff
|
|
*
|
|
* NB: heap_abort_speculative() uses the same xlog record and replay
|
|
* routines.
|
|
*/
|
|
if (RelationNeedsWAL(relation))
|
|
{
|
|
xl_heap_delete xlrec;
|
|
XLogRecPtr recptr;
|
|
|
|
/* For logical decode we need combocids to properly decode the catalog */
|
|
if (RelationIsAccessibleInLogicalDecoding(relation))
|
|
log_heap_new_cid(relation, &tp);
|
|
|
|
xlrec.flags = all_visible_cleared ? XLH_DELETE_ALL_VISIBLE_CLEARED : 0;
|
|
xlrec.infobits_set = compute_infobits(tp.t_data->t_infomask,
|
|
tp.t_data->t_infomask2);
|
|
xlrec.offnum = ItemPointerGetOffsetNumber(&tp.t_self);
|
|
xlrec.xmax = new_xmax;
|
|
|
|
if (old_key_tuple != NULL)
|
|
{
|
|
if (relation->rd_rel->relreplident == REPLICA_IDENTITY_FULL)
|
|
xlrec.flags |= XLH_DELETE_CONTAINS_OLD_TUPLE;
|
|
else
|
|
xlrec.flags |= XLH_DELETE_CONTAINS_OLD_KEY;
|
|
}
|
|
|
|
XLogBeginInsert();
|
|
XLogRegisterData((char *) &xlrec, SizeOfHeapDelete);
|
|
|
|
XLogRegisterBuffer(0, buffer, REGBUF_STANDARD);
|
|
|
|
/*
|
|
* Log replica identity of the deleted tuple if there is one
|
|
*/
|
|
if (old_key_tuple != NULL)
|
|
{
|
|
xl_heap_header xlhdr;
|
|
|
|
xlhdr.t_infomask2 = old_key_tuple->t_data->t_infomask2;
|
|
xlhdr.t_infomask = old_key_tuple->t_data->t_infomask;
|
|
xlhdr.t_hoff = old_key_tuple->t_data->t_hoff;
|
|
|
|
XLogRegisterData((char *) &xlhdr, SizeOfHeapHeader);
|
|
XLogRegisterData((char *) old_key_tuple->t_data
|
|
+ SizeofHeapTupleHeader,
|
|
old_key_tuple->t_len
|
|
- SizeofHeapTupleHeader);
|
|
}
|
|
|
|
/* filtering by origin on a row level is much more efficient */
|
|
XLogSetRecordFlags(XLOG_INCLUDE_ORIGIN);
|
|
|
|
recptr = XLogInsert(RM_HEAP_ID, XLOG_HEAP_DELETE);
|
|
|
|
PageSetLSN(page, recptr);
|
|
}
|
|
|
|
END_CRIT_SECTION();
|
|
|
|
LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
|
|
|
|
if (vmbuffer != InvalidBuffer)
|
|
ReleaseBuffer(vmbuffer);
|
|
|
|
/*
|
|
* If the tuple has toasted out-of-line attributes, we need to delete
|
|
* those items too. We have to do this before releasing the buffer
|
|
* because we need to look at the contents of the tuple, but it's OK to
|
|
* release the content lock on the buffer first.
|
|
*/
|
|
if (relation->rd_rel->relkind != RELKIND_RELATION &&
|
|
relation->rd_rel->relkind != RELKIND_MATVIEW)
|
|
{
|
|
/* toast table entries should never be recursively toasted */
|
|
Assert(!HeapTupleHasExternal(&tp));
|
|
}
|
|
else if (HeapTupleHasExternal(&tp))
|
|
toast_delete(relation, &tp, false);
|
|
|
|
/*
|
|
* Mark tuple for invalidation from system caches at next command
|
|
* boundary. We have to do this before releasing the buffer because we
|
|
* need to look at the contents of the tuple.
|
|
*/
|
|
CacheInvalidateHeapTuple(relation, &tp, NULL);
|
|
|
|
/* Now we can release the buffer */
|
|
ReleaseBuffer(buffer);
|
|
|
|
/*
|
|
* Release the lmgr tuple lock, if we had it.
|
|
*/
|
|
if (have_tuple_lock)
|
|
UnlockTupleTuplock(relation, &(tp.t_self), LockTupleExclusive);
|
|
|
|
pgstat_count_heap_delete(relation);
|
|
|
|
if (old_key_tuple != NULL && old_key_copied)
|
|
heap_freetuple(old_key_tuple);
|
|
|
|
return HeapTupleMayBeUpdated;
|
|
}
|
|
|
|
/*
|
|
* simple_heap_delete - delete a tuple
|
|
*
|
|
* This routine may be used to delete a tuple when concurrent updates of
|
|
* the target tuple are not expected (for example, because we have a lock
|
|
* on the relation associated with the tuple). Any failure is reported
|
|
* via ereport().
|
|
*/
|
|
void
|
|
simple_heap_delete(Relation relation, ItemPointer tid)
|
|
{
|
|
HTSU_Result result;
|
|
HeapUpdateFailureData hufd;
|
|
|
|
result = heap_delete(relation, tid,
|
|
GetCurrentCommandId(true), InvalidSnapshot,
|
|
true /* wait for commit */ ,
|
|
&hufd);
|
|
switch (result)
|
|
{
|
|
case HeapTupleSelfUpdated:
|
|
/* Tuple was already updated in current command? */
|
|
elog(ERROR, "tuple already updated by self");
|
|
break;
|
|
|
|
case HeapTupleMayBeUpdated:
|
|
/* done successfully */
|
|
break;
|
|
|
|
case HeapTupleUpdated:
|
|
elog(ERROR, "tuple concurrently updated");
|
|
break;
|
|
|
|
default:
|
|
elog(ERROR, "unrecognized heap_delete status: %u", result);
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* heap_update - replace a tuple
|
|
*
|
|
* NB: do not call this directly unless you are prepared to deal with
|
|
* concurrent-update conditions. Use simple_heap_update instead.
|
|
*
|
|
* relation - table to be modified (caller must hold suitable lock)
|
|
* otid - TID of old tuple to be replaced
|
|
* newtup - newly constructed tuple data to store
|
|
* cid - update command ID (used for visibility test, and stored into
|
|
* cmax/cmin if successful)
|
|
* crosscheck - if not InvalidSnapshot, also check old tuple against this
|
|
* wait - true if should wait for any conflicting update to commit/abort
|
|
* hufd - output parameter, filled in failure cases (see below)
|
|
* lockmode - output parameter, filled with lock mode acquired on tuple
|
|
*
|
|
* Normal, successful return value is HeapTupleMayBeUpdated, which
|
|
* actually means we *did* update it. Failure return codes are
|
|
* HeapTupleSelfUpdated, HeapTupleUpdated, or HeapTupleBeingUpdated
|
|
* (the last only possible if wait == false).
|
|
*
|
|
* On success, the header fields of *newtup are updated to match the new
|
|
* stored tuple; in particular, newtup->t_self is set to the TID where the
|
|
* new tuple was inserted, and its HEAP_ONLY_TUPLE flag is set iff a HOT
|
|
* update was done. However, any TOAST changes in the new tuple's
|
|
* data are not reflected into *newtup.
|
|
*
|
|
* In the failure cases, the routine fills *hufd with the tuple's t_ctid,
|
|
* t_xmax (resolving a possible MultiXact, if necessary), and t_cmax
|
|
* (the last only for HeapTupleSelfUpdated, since we
|
|
* cannot obtain cmax from a combocid generated by another transaction).
|
|
* See comments for struct HeapUpdateFailureData for additional info.
|
|
*/
|
|
HTSU_Result
|
|
heap_update(Relation relation, ItemPointer otid, HeapTuple newtup,
|
|
CommandId cid, Snapshot crosscheck, bool wait,
|
|
HeapUpdateFailureData *hufd, LockTupleMode *lockmode)
|
|
{
|
|
HTSU_Result result;
|
|
TransactionId xid = GetCurrentTransactionId();
|
|
Bitmapset *hot_attrs;
|
|
Bitmapset *key_attrs;
|
|
Bitmapset *id_attrs;
|
|
Bitmapset *interesting_attrs;
|
|
Bitmapset *modified_attrs;
|
|
ItemId lp;
|
|
HeapTupleData oldtup;
|
|
HeapTuple heaptup;
|
|
HeapTuple old_key_tuple = NULL;
|
|
bool old_key_copied = false;
|
|
Page page;
|
|
BlockNumber block;
|
|
MultiXactStatus mxact_status;
|
|
Buffer buffer,
|
|
newbuf,
|
|
vmbuffer = InvalidBuffer,
|
|
vmbuffer_new = InvalidBuffer;
|
|
bool need_toast;
|
|
Size newtupsize,
|
|
pagefree;
|
|
bool have_tuple_lock = false;
|
|
bool iscombo;
|
|
bool use_hot_update = false;
|
|
bool hot_attrs_checked = false;
|
|
bool key_intact;
|
|
bool all_visible_cleared = false;
|
|
bool all_visible_cleared_new = false;
|
|
bool checked_lockers;
|
|
bool locker_remains;
|
|
TransactionId xmax_new_tuple,
|
|
xmax_old_tuple;
|
|
uint16 infomask_old_tuple,
|
|
infomask2_old_tuple,
|
|
infomask_new_tuple,
|
|
infomask2_new_tuple;
|
|
|
|
Assert(ItemPointerIsValid(otid));
|
|
|
|
/*
|
|
* Forbid this during a parallel operation, lest it allocate a combocid.
|
|
* Other workers might need that combocid for visibility checks, and we
|
|
* have no provision for broadcasting it to them.
|
|
*/
|
|
if (IsInParallelMode())
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_INVALID_TRANSACTION_STATE),
|
|
errmsg("cannot update tuples during a parallel operation")));
|
|
|
|
/*
|
|
* Fetch the list of attributes to be checked for various operations.
|
|
*
|
|
* For HOT considerations, this is wasted effort if we fail to update or
|
|
* have to put the new tuple on a different page. But we must compute the
|
|
* list before obtaining buffer lock --- in the worst case, if we are
|
|
* doing an update on one of the relevant system catalogs, we could
|
|
* deadlock if we try to fetch the list later. In any case, the relcache
|
|
* caches the data so this is usually pretty cheap.
|
|
*
|
|
* We also need columns used by the replica identity and columns that are
|
|
* considered the "key" of rows in the table.
|
|
*
|
|
* Note that we get copies of each bitmap, so we need not worry about
|
|
* relcache flush happening midway through.
|
|
*/
|
|
hot_attrs = RelationGetIndexAttrBitmap(relation, INDEX_ATTR_BITMAP_ALL);
|
|
key_attrs = RelationGetIndexAttrBitmap(relation, INDEX_ATTR_BITMAP_KEY);
|
|
id_attrs = RelationGetIndexAttrBitmap(relation,
|
|
INDEX_ATTR_BITMAP_IDENTITY_KEY);
|
|
|
|
|
|
block = ItemPointerGetBlockNumber(otid);
|
|
buffer = ReadBuffer(relation, block);
|
|
page = BufferGetPage(buffer);
|
|
|
|
interesting_attrs = NULL;
|
|
|
|
/*
|
|
* If the page is already full, there is hardly any chance of doing a HOT
|
|
* update on this page. It might be wasteful effort to look for index
|
|
* column updates only to later reject HOT updates for lack of space in
|
|
* the same page. So we be conservative and only fetch hot_attrs if the
|
|
* page is not already full. Since we are already holding a pin on the
|
|
* buffer, there is no chance that the buffer can get cleaned up
|
|
* concurrently and even if that was possible, in the worst case we lose a
|
|
* chance to do a HOT update.
|
|
*/
|
|
if (!PageIsFull(page))
|
|
{
|
|
interesting_attrs = bms_add_members(interesting_attrs, hot_attrs);
|
|
hot_attrs_checked = true;
|
|
}
|
|
interesting_attrs = bms_add_members(interesting_attrs, key_attrs);
|
|
interesting_attrs = bms_add_members(interesting_attrs, id_attrs);
|
|
|
|
/*
|
|
* Before locking the buffer, pin the visibility map page if it appears to
|
|
* be necessary. Since we haven't got the lock yet, someone else might be
|
|
* in the middle of changing this, so we'll need to recheck after we have
|
|
* the lock.
|
|
*/
|
|
if (PageIsAllVisible(page))
|
|
visibilitymap_pin(relation, block, &vmbuffer);
|
|
|
|
LockBuffer(buffer, BUFFER_LOCK_EXCLUSIVE);
|
|
|
|
lp = PageGetItemId(page, ItemPointerGetOffsetNumber(otid));
|
|
Assert(ItemIdIsNormal(lp));
|
|
|
|
/*
|
|
* Fill in enough data in oldtup for HeapDetermineModifiedColumns to work
|
|
* properly.
|
|
*/
|
|
oldtup.t_tableOid = RelationGetRelid(relation);
|
|
oldtup.t_data = (HeapTupleHeader) PageGetItem(page, lp);
|
|
oldtup.t_len = ItemIdGetLength(lp);
|
|
oldtup.t_self = *otid;
|
|
|
|
/* the new tuple is ready, except for this: */
|
|
newtup->t_tableOid = RelationGetRelid(relation);
|
|
|
|
/* Fill in OID for newtup */
|
|
if (relation->rd_rel->relhasoids)
|
|
{
|
|
#ifdef NOT_USED
|
|
/* this is redundant with an Assert in HeapTupleSetOid */
|
|
Assert(newtup->t_data->t_infomask & HEAP_HASOID);
|
|
#endif
|
|
HeapTupleSetOid(newtup, HeapTupleGetOid(&oldtup));
|
|
}
|
|
else
|
|
{
|
|
/* check there is not space for an OID */
|
|
Assert(!(newtup->t_data->t_infomask & HEAP_HASOID));
|
|
}
|
|
|
|
/* Determine columns modified by the update. */
|
|
modified_attrs = HeapDetermineModifiedColumns(relation, interesting_attrs,
|
|
&oldtup, newtup);
|
|
|
|
/*
|
|
* If we're not updating any "key" column, we can grab a weaker lock type.
|
|
* This allows for more concurrency when we are running simultaneously
|
|
* with foreign key checks.
|
|
*
|
|
* Note that if a column gets detoasted while executing the update, but
|
|
* the value ends up being the same, this test will fail and we will use
|
|
* the stronger lock. This is acceptable; the important case to optimize
|
|
* is updates that don't manipulate key columns, not those that
|
|
* serendipitiously arrive at the same key values.
|
|
*/
|
|
if (!bms_overlap(modified_attrs, key_attrs))
|
|
{
|
|
*lockmode = LockTupleNoKeyExclusive;
|
|
mxact_status = MultiXactStatusNoKeyUpdate;
|
|
key_intact = true;
|
|
|
|
/*
|
|
* If this is the first possibly-multixact-able operation in the
|
|
* current transaction, set my per-backend OldestMemberMXactId
|
|
* setting. We can be certain that the transaction will never become a
|
|
* member of any older MultiXactIds than that. (We have to do this
|
|
* even if we end up just using our own TransactionId below, since
|
|
* some other backend could incorporate our XID into a MultiXact
|
|
* immediately afterwards.)
|
|
*/
|
|
MultiXactIdSetOldestMember();
|
|
}
|
|
else
|
|
{
|
|
*lockmode = LockTupleExclusive;
|
|
mxact_status = MultiXactStatusUpdate;
|
|
key_intact = false;
|
|
}
|
|
|
|
/*
|
|
* Note: beyond this point, use oldtup not otid to refer to old tuple.
|
|
* otid may very well point at newtup->t_self, which we will overwrite
|
|
* with the new tuple's location, so there's great risk of confusion if we
|
|
* use otid anymore.
|
|
*/
|
|
|
|
l2:
|
|
checked_lockers = false;
|
|
locker_remains = false;
|
|
result = HeapTupleSatisfiesUpdate(&oldtup, cid, buffer);
|
|
|
|
/* see below about the "no wait" case */
|
|
Assert(result != HeapTupleBeingUpdated || wait);
|
|
|
|
if (result == HeapTupleInvisible)
|
|
{
|
|
UnlockReleaseBuffer(buffer);
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
|
|
errmsg("attempted to update invisible tuple")));
|
|
}
|
|
else if (result == HeapTupleBeingUpdated && wait)
|
|
{
|
|
TransactionId xwait;
|
|
uint16 infomask;
|
|
bool can_continue = false;
|
|
|
|
/*
|
|
* XXX note that we don't consider the "no wait" case here. This
|
|
* isn't a problem currently because no caller uses that case, but it
|
|
* should be fixed if such a caller is introduced. It wasn't a
|
|
* problem previously because this code would always wait, but now
|
|
* that some tuple locks do not conflict with one of the lock modes we
|
|
* use, it is possible that this case is interesting to handle
|
|
* specially.
|
|
*
|
|
* This may cause failures with third-party code that calls
|
|
* heap_update directly.
|
|
*/
|
|
|
|
/* must copy state data before unlocking buffer */
|
|
xwait = HeapTupleHeaderGetRawXmax(oldtup.t_data);
|
|
infomask = oldtup.t_data->t_infomask;
|
|
|
|
/*
|
|
* Now we have to do something about the existing locker. If it's a
|
|
* multi, sleep on it; we might be awakened before it is completely
|
|
* gone (or even not sleep at all in some cases); we need to preserve
|
|
* it as locker, unless it is gone completely.
|
|
*
|
|
* If it's not a multi, we need to check for sleeping conditions
|
|
* before actually going to sleep. If the update doesn't conflict
|
|
* with the locks, we just continue without sleeping (but making sure
|
|
* it is preserved).
|
|
*
|
|
* Before sleeping, we need to acquire tuple lock to establish our
|
|
* priority for the tuple (see heap_lock_tuple). LockTuple will
|
|
* release us when we are next-in-line for the tuple. Note we must
|
|
* not acquire the tuple lock until we're sure we're going to sleep;
|
|
* otherwise we're open for race conditions with other transactions
|
|
* holding the tuple lock which sleep on us.
|
|
*
|
|
* If we are forced to "start over" below, we keep the tuple lock;
|
|
* this arranges that we stay at the head of the line while rechecking
|
|
* tuple state.
|
|
*/
|
|
if (infomask & HEAP_XMAX_IS_MULTI)
|
|
{
|
|
TransactionId update_xact;
|
|
int remain;
|
|
|
|
if (DoesMultiXactIdConflict((MultiXactId) xwait, infomask,
|
|
*lockmode))
|
|
{
|
|
LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
|
|
|
|
/* acquire tuple lock, if necessary */
|
|
heap_acquire_tuplock(relation, &(oldtup.t_self), *lockmode,
|
|
LockWaitBlock, &have_tuple_lock);
|
|
|
|
/* wait for multixact */
|
|
MultiXactIdWait((MultiXactId) xwait, mxact_status, infomask,
|
|
relation, &oldtup.t_self, XLTW_Update,
|
|
&remain);
|
|
checked_lockers = true;
|
|
locker_remains = remain != 0;
|
|
LockBuffer(buffer, BUFFER_LOCK_EXCLUSIVE);
|
|
|
|
/*
|
|
* If xwait had just locked the tuple then some other xact
|
|
* could update this tuple before we get to this point. Check
|
|
* for xmax change, and start over if so.
|
|
*/
|
|
if (xmax_infomask_changed(oldtup.t_data->t_infomask,
|
|
infomask) ||
|
|
!TransactionIdEquals(HeapTupleHeaderGetRawXmax(oldtup.t_data),
|
|
xwait))
|
|
goto l2;
|
|
}
|
|
|
|
/*
|
|
* Note that the multixact may not be done by now. It could have
|
|
* surviving members; our own xact or other subxacts of this
|
|
* backend, and also any other concurrent transaction that locked
|
|
* the tuple with KeyShare if we only got TupleLockUpdate. If
|
|
* this is the case, we have to be careful to mark the updated
|
|
* tuple with the surviving members in Xmax.
|
|
*
|
|
* Note that there could have been another update in the
|
|
* MultiXact. In that case, we need to check whether it committed
|
|
* or aborted. If it aborted we are safe to update it again;
|
|
* otherwise there is an update conflict, and we have to return
|
|
* HeapTupleUpdated below.
|
|
*
|
|
* In the LockTupleExclusive case, we still need to preserve the
|
|
* surviving members: those would include the tuple locks we had
|
|
* before this one, which are important to keep in case this
|
|
* subxact aborts.
|
|
*/
|
|
if (!HEAP_XMAX_IS_LOCKED_ONLY(oldtup.t_data->t_infomask))
|
|
update_xact = HeapTupleGetUpdateXid(oldtup.t_data);
|
|
else
|
|
update_xact = InvalidTransactionId;
|
|
|
|
/*
|
|
* There was no UPDATE in the MultiXact; or it aborted. No
|
|
* TransactionIdIsInProgress() call needed here, since we called
|
|
* MultiXactIdWait() above.
|
|
*/
|
|
if (!TransactionIdIsValid(update_xact) ||
|
|
TransactionIdDidAbort(update_xact))
|
|
can_continue = true;
|
|
}
|
|
else if (TransactionIdIsCurrentTransactionId(xwait))
|
|
{
|
|
/*
|
|
* The only locker is ourselves; we can avoid grabbing the tuple
|
|
* lock here, but must preserve our locking information.
|
|
*/
|
|
checked_lockers = true;
|
|
locker_remains = true;
|
|
can_continue = true;
|
|
}
|
|
else if (HEAP_XMAX_IS_KEYSHR_LOCKED(infomask) && key_intact)
|
|
{
|
|
/*
|
|
* If it's just a key-share locker, and we're not changing the key
|
|
* columns, we don't need to wait for it to end; but we need to
|
|
* preserve it as locker.
|
|
*/
|
|
checked_lockers = true;
|
|
locker_remains = true;
|
|
can_continue = true;
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* Wait for regular transaction to end; but first, acquire tuple
|
|
* lock.
|
|
*/
|
|
LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
|
|
heap_acquire_tuplock(relation, &(oldtup.t_self), *lockmode,
|
|
LockWaitBlock, &have_tuple_lock);
|
|
XactLockTableWait(xwait, relation, &oldtup.t_self,
|
|
XLTW_Update);
|
|
checked_lockers = true;
|
|
LockBuffer(buffer, BUFFER_LOCK_EXCLUSIVE);
|
|
|
|
/*
|
|
* xwait is done, but if xwait had just locked the tuple then some
|
|
* other xact could update this tuple before we get to this point.
|
|
* Check for xmax change, and start over if so.
|
|
*/
|
|
if (xmax_infomask_changed(oldtup.t_data->t_infomask, infomask) ||
|
|
!TransactionIdEquals(xwait,
|
|
HeapTupleHeaderGetRawXmax(oldtup.t_data)))
|
|
goto l2;
|
|
|
|
/* Otherwise check if it committed or aborted */
|
|
UpdateXmaxHintBits(oldtup.t_data, buffer, xwait);
|
|
if (oldtup.t_data->t_infomask & HEAP_XMAX_INVALID)
|
|
can_continue = true;
|
|
}
|
|
|
|
result = can_continue ? HeapTupleMayBeUpdated : HeapTupleUpdated;
|
|
}
|
|
|
|
if (crosscheck != InvalidSnapshot && result == HeapTupleMayBeUpdated)
|
|
{
|
|
/* Perform additional check for transaction-snapshot mode RI updates */
|
|
if (!HeapTupleSatisfiesVisibility(&oldtup, crosscheck, buffer))
|
|
result = HeapTupleUpdated;
|
|
}
|
|
|
|
if (result != HeapTupleMayBeUpdated)
|
|
{
|
|
Assert(result == HeapTupleSelfUpdated ||
|
|
result == HeapTupleUpdated ||
|
|
result == HeapTupleBeingUpdated);
|
|
Assert(!(oldtup.t_data->t_infomask & HEAP_XMAX_INVALID));
|
|
hufd->ctid = oldtup.t_data->t_ctid;
|
|
hufd->xmax = HeapTupleHeaderGetUpdateXid(oldtup.t_data);
|
|
if (result == HeapTupleSelfUpdated)
|
|
hufd->cmax = HeapTupleHeaderGetCmax(oldtup.t_data);
|
|
else
|
|
hufd->cmax = InvalidCommandId;
|
|
UnlockReleaseBuffer(buffer);
|
|
if (have_tuple_lock)
|
|
UnlockTupleTuplock(relation, &(oldtup.t_self), *lockmode);
|
|
if (vmbuffer != InvalidBuffer)
|
|
ReleaseBuffer(vmbuffer);
|
|
bms_free(hot_attrs);
|
|
bms_free(key_attrs);
|
|
bms_free(id_attrs);
|
|
bms_free(modified_attrs);
|
|
bms_free(interesting_attrs);
|
|
return result;
|
|
}
|
|
|
|
/*
|
|
* If we didn't pin the visibility map page and the page has become all
|
|
* visible while we were busy locking the buffer, or during some
|
|
* subsequent window during which we had it unlocked, we'll have to unlock
|
|
* and re-lock, to avoid holding the buffer lock across an I/O. That's a
|
|
* bit unfortunate, especially since we'll now have to recheck whether the
|
|
* tuple has been locked or updated under us, but hopefully it won't
|
|
* happen very often.
|
|
*/
|
|
if (vmbuffer == InvalidBuffer && PageIsAllVisible(page))
|
|
{
|
|
LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
|
|
visibilitymap_pin(relation, block, &vmbuffer);
|
|
LockBuffer(buffer, BUFFER_LOCK_EXCLUSIVE);
|
|
goto l2;
|
|
}
|
|
|
|
/* Fill in transaction status data */
|
|
|
|
/*
|
|
* If the tuple we're updating is locked, we need to preserve the locking
|
|
* info in the old tuple's Xmax. Prepare a new Xmax value for this.
|
|
*/
|
|
compute_new_xmax_infomask(HeapTupleHeaderGetRawXmax(oldtup.t_data),
|
|
oldtup.t_data->t_infomask,
|
|
oldtup.t_data->t_infomask2,
|
|
xid, *lockmode, true,
|
|
&xmax_old_tuple, &infomask_old_tuple,
|
|
&infomask2_old_tuple);
|
|
|
|
/*
|
|
* And also prepare an Xmax value for the new copy of the tuple. If there
|
|
* was no xmax previously, or there was one but all lockers are now gone,
|
|
* then use InvalidXid; otherwise, get the xmax from the old tuple. (In
|
|
* rare cases that might also be InvalidXid and yet not have the
|
|
* HEAP_XMAX_INVALID bit set; that's fine.)
|
|
*/
|
|
if ((oldtup.t_data->t_infomask & HEAP_XMAX_INVALID) ||
|
|
HEAP_LOCKED_UPGRADED(oldtup.t_data->t_infomask) ||
|
|
(checked_lockers && !locker_remains))
|
|
xmax_new_tuple = InvalidTransactionId;
|
|
else
|
|
xmax_new_tuple = HeapTupleHeaderGetRawXmax(oldtup.t_data);
|
|
|
|
if (!TransactionIdIsValid(xmax_new_tuple))
|
|
{
|
|
infomask_new_tuple = HEAP_XMAX_INVALID;
|
|
infomask2_new_tuple = 0;
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* If we found a valid Xmax for the new tuple, then the infomask bits
|
|
* to use on the new tuple depend on what was there on the old one.
|
|
* Note that since we're doing an update, the only possibility is that
|
|
* the lockers had FOR KEY SHARE lock.
|
|
*/
|
|
if (oldtup.t_data->t_infomask & HEAP_XMAX_IS_MULTI)
|
|
{
|
|
GetMultiXactIdHintBits(xmax_new_tuple, &infomask_new_tuple,
|
|
&infomask2_new_tuple);
|
|
}
|
|
else
|
|
{
|
|
infomask_new_tuple = HEAP_XMAX_KEYSHR_LOCK | HEAP_XMAX_LOCK_ONLY;
|
|
infomask2_new_tuple = 0;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Prepare the new tuple with the appropriate initial values of Xmin and
|
|
* Xmax, as well as initial infomask bits as computed above.
|
|
*/
|
|
newtup->t_data->t_infomask &= ~(HEAP_XACT_MASK);
|
|
newtup->t_data->t_infomask2 &= ~(HEAP2_XACT_MASK);
|
|
HeapTupleHeaderSetXmin(newtup->t_data, xid);
|
|
HeapTupleHeaderSetCmin(newtup->t_data, cid);
|
|
newtup->t_data->t_infomask |= HEAP_UPDATED | infomask_new_tuple;
|
|
newtup->t_data->t_infomask2 |= infomask2_new_tuple;
|
|
HeapTupleHeaderSetXmax(newtup->t_data, xmax_new_tuple);
|
|
|
|
/*
|
|
* Replace cid with a combo cid if necessary. Note that we already put
|
|
* the plain cid into the new tuple.
|
|
*/
|
|
HeapTupleHeaderAdjustCmax(oldtup.t_data, &cid, &iscombo);
|
|
|
|
/*
|
|
* If the toaster needs to be activated, OR if the new tuple will not fit
|
|
* on the same page as the old, then we need to release the content lock
|
|
* (but not the pin!) on the old tuple's buffer while we are off doing
|
|
* TOAST and/or table-file-extension work. We must mark the old tuple to
|
|
* show that it's locked, else other processes may try to update it
|
|
* themselves.
|
|
*
|
|
* We need to invoke the toaster if there are already any out-of-line
|
|
* toasted values present, or if the new tuple is over-threshold.
|
|
*/
|
|
if (relation->rd_rel->relkind != RELKIND_RELATION &&
|
|
relation->rd_rel->relkind != RELKIND_MATVIEW)
|
|
{
|
|
/* toast table entries should never be recursively toasted */
|
|
Assert(!HeapTupleHasExternal(&oldtup));
|
|
Assert(!HeapTupleHasExternal(newtup));
|
|
need_toast = false;
|
|
}
|
|
else
|
|
need_toast = (HeapTupleHasExternal(&oldtup) ||
|
|
HeapTupleHasExternal(newtup) ||
|
|
newtup->t_len > TOAST_TUPLE_THRESHOLD);
|
|
|
|
pagefree = PageGetHeapFreeSpace(page);
|
|
|
|
newtupsize = MAXALIGN(newtup->t_len);
|
|
|
|
if (need_toast || newtupsize > pagefree)
|
|
{
|
|
TransactionId xmax_lock_old_tuple;
|
|
uint16 infomask_lock_old_tuple,
|
|
infomask2_lock_old_tuple;
|
|
bool cleared_all_frozen = false;
|
|
|
|
/*
|
|
* To prevent concurrent sessions from updating the tuple, we have to
|
|
* temporarily mark it locked, while we release the page-level lock.
|
|
*
|
|
* To satisfy the rule that any xid potentially appearing in a buffer
|
|
* written out to disk, we unfortunately have to WAL log this
|
|
* temporary modification. We can reuse xl_heap_lock for this
|
|
* purpose. If we crash/error before following through with the
|
|
* actual update, xmax will be of an aborted transaction, allowing
|
|
* other sessions to proceed.
|
|
*/
|
|
|
|
/*
|
|
* Compute xmax / infomask appropriate for locking the tuple. This has
|
|
* to be done separately from the combo that's going to be used for
|
|
* updating, because the potentially created multixact would otherwise
|
|
* be wrong.
|
|
*/
|
|
compute_new_xmax_infomask(HeapTupleHeaderGetRawXmax(oldtup.t_data),
|
|
oldtup.t_data->t_infomask,
|
|
oldtup.t_data->t_infomask2,
|
|
xid, *lockmode, false,
|
|
&xmax_lock_old_tuple, &infomask_lock_old_tuple,
|
|
&infomask2_lock_old_tuple);
|
|
|
|
Assert(HEAP_XMAX_IS_LOCKED_ONLY(infomask_lock_old_tuple));
|
|
|
|
START_CRIT_SECTION();
|
|
|
|
/* Clear obsolete visibility flags ... */
|
|
oldtup.t_data->t_infomask &= ~(HEAP_XMAX_BITS | HEAP_MOVED);
|
|
oldtup.t_data->t_infomask2 &= ~HEAP_KEYS_UPDATED;
|
|
HeapTupleClearHotUpdated(&oldtup);
|
|
/* ... and store info about transaction updating this tuple */
|
|
Assert(TransactionIdIsValid(xmax_lock_old_tuple));
|
|
HeapTupleHeaderSetXmax(oldtup.t_data, xmax_lock_old_tuple);
|
|
oldtup.t_data->t_infomask |= infomask_lock_old_tuple;
|
|
oldtup.t_data->t_infomask2 |= infomask2_lock_old_tuple;
|
|
HeapTupleHeaderSetCmax(oldtup.t_data, cid, iscombo);
|
|
|
|
/* temporarily make it look not-updated, but locked */
|
|
oldtup.t_data->t_ctid = oldtup.t_self;
|
|
|
|
/*
|
|
* Clear all-frozen bit on visibility map if needed. We could
|
|
* immediately reset ALL_VISIBLE, but given that the WAL logging
|
|
* overhead would be unchanged, that doesn't seem necessarily
|
|
* worthwhile.
|
|
*/
|
|
if (PageIsAllVisible(BufferGetPage(buffer)) &&
|
|
visibilitymap_clear(relation, block, vmbuffer,
|
|
VISIBILITYMAP_ALL_FROZEN))
|
|
cleared_all_frozen = true;
|
|
|
|
MarkBufferDirty(buffer);
|
|
|
|
if (RelationNeedsWAL(relation))
|
|
{
|
|
xl_heap_lock xlrec;
|
|
XLogRecPtr recptr;
|
|
|
|
XLogBeginInsert();
|
|
XLogRegisterBuffer(0, buffer, REGBUF_STANDARD);
|
|
|
|
xlrec.offnum = ItemPointerGetOffsetNumber(&oldtup.t_self);
|
|
xlrec.locking_xid = xmax_lock_old_tuple;
|
|
xlrec.infobits_set = compute_infobits(oldtup.t_data->t_infomask,
|
|
oldtup.t_data->t_infomask2);
|
|
xlrec.flags =
|
|
cleared_all_frozen ? XLH_LOCK_ALL_FROZEN_CLEARED : 0;
|
|
XLogRegisterData((char *) &xlrec, SizeOfHeapLock);
|
|
recptr = XLogInsert(RM_HEAP_ID, XLOG_HEAP_LOCK);
|
|
PageSetLSN(page, recptr);
|
|
}
|
|
|
|
END_CRIT_SECTION();
|
|
|
|
LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
|
|
|
|
/*
|
|
* Let the toaster do its thing, if needed.
|
|
*
|
|
* Note: below this point, heaptup is the data we actually intend to
|
|
* store into the relation; newtup is the caller's original untoasted
|
|
* data.
|
|
*/
|
|
if (need_toast)
|
|
{
|
|
/* Note we always use WAL and FSM during updates */
|
|
heaptup = toast_insert_or_update(relation, newtup, &oldtup, 0);
|
|
newtupsize = MAXALIGN(heaptup->t_len);
|
|
}
|
|
else
|
|
heaptup = newtup;
|
|
|
|
/*
|
|
* Now, do we need a new page for the tuple, or not? This is a bit
|
|
* tricky since someone else could have added tuples to the page while
|
|
* we weren't looking. We have to recheck the available space after
|
|
* reacquiring the buffer lock. But don't bother to do that if the
|
|
* former amount of free space is still not enough; it's unlikely
|
|
* there's more free now than before.
|
|
*
|
|
* What's more, if we need to get a new page, we will need to acquire
|
|
* buffer locks on both old and new pages. To avoid deadlock against
|
|
* some other backend trying to get the same two locks in the other
|
|
* order, we must be consistent about the order we get the locks in.
|
|
* We use the rule "lock the lower-numbered page of the relation
|
|
* first". To implement this, we must do RelationGetBufferForTuple
|
|
* while not holding the lock on the old page, and we must rely on it
|
|
* to get the locks on both pages in the correct order.
|
|
*/
|
|
if (newtupsize > pagefree)
|
|
{
|
|
/* Assume there's no chance to put heaptup on same page. */
|
|
newbuf = RelationGetBufferForTuple(relation, heaptup->t_len,
|
|
buffer, 0, NULL,
|
|
&vmbuffer_new, &vmbuffer);
|
|
}
|
|
else
|
|
{
|
|
/* Re-acquire the lock on the old tuple's page. */
|
|
LockBuffer(buffer, BUFFER_LOCK_EXCLUSIVE);
|
|
/* Re-check using the up-to-date free space */
|
|
pagefree = PageGetHeapFreeSpace(page);
|
|
if (newtupsize > pagefree)
|
|
{
|
|
/*
|
|
* Rats, it doesn't fit anymore. We must now unlock and
|
|
* relock to avoid deadlock. Fortunately, this path should
|
|
* seldom be taken.
|
|
*/
|
|
LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
|
|
newbuf = RelationGetBufferForTuple(relation, heaptup->t_len,
|
|
buffer, 0, NULL,
|
|
&vmbuffer_new, &vmbuffer);
|
|
}
|
|
else
|
|
{
|
|
/* OK, it fits here, so we're done. */
|
|
newbuf = buffer;
|
|
}
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* No TOAST work needed, and it'll fit on same page */
|
|
newbuf = buffer;
|
|
heaptup = newtup;
|
|
}
|
|
|
|
/*
|
|
* We're about to do the actual update -- check for conflict first, to
|
|
* avoid possibly having to roll back work we've just done.
|
|
*
|
|
* This is safe without a recheck as long as there is no possibility of
|
|
* another process scanning the pages between this check and the update
|
|
* being visible to the scan (i.e., exclusive buffer content lock(s) are
|
|
* continuously held from this point until the tuple update is visible).
|
|
*
|
|
* For the new tuple the only check needed is at the relation level, but
|
|
* since both tuples are in the same relation and the check for oldtup
|
|
* will include checking the relation level, there is no benefit to a
|
|
* separate check for the new tuple.
|
|
*/
|
|
CheckForSerializableConflictIn(relation, &oldtup, buffer);
|
|
|
|
/*
|
|
* At this point newbuf and buffer are both pinned and locked, and newbuf
|
|
* has enough space for the new tuple. If they are the same buffer, only
|
|
* one pin is held.
|
|
*/
|
|
|
|
if (newbuf == buffer)
|
|
{
|
|
/*
|
|
* Since the new tuple is going into the same page, we might be able
|
|
* to do a HOT update. Check if any of the index columns have been
|
|
* changed. If the page was already full, we may have skipped checking
|
|
* for index columns. If so, HOT update is possible.
|
|
*/
|
|
if (hot_attrs_checked && !bms_overlap(modified_attrs, hot_attrs))
|
|
use_hot_update = true;
|
|
}
|
|
else
|
|
{
|
|
/* Set a hint that the old page could use prune/defrag */
|
|
PageSetFull(page);
|
|
}
|
|
|
|
/*
|
|
* Compute replica identity tuple before entering the critical section so
|
|
* we don't PANIC upon a memory allocation failure.
|
|
* ExtractReplicaIdentity() will return NULL if nothing needs to be
|
|
* logged.
|
|
*/
|
|
old_key_tuple = ExtractReplicaIdentity(relation, &oldtup,
|
|
bms_overlap(modified_attrs, id_attrs),
|
|
&old_key_copied);
|
|
|
|
/* NO EREPORT(ERROR) from here till changes are logged */
|
|
START_CRIT_SECTION();
|
|
|
|
/*
|
|
* If this transaction commits, the old tuple will become DEAD sooner or
|
|
* later. Set flag that this page is a candidate for pruning once our xid
|
|
* falls below the OldestXmin horizon. If the transaction finally aborts,
|
|
* the subsequent page pruning will be a no-op and the hint will be
|
|
* cleared.
|
|
*
|
|
* XXX Should we set hint on newbuf as well? If the transaction aborts,
|
|
* there would be a prunable tuple in the newbuf; but for now we choose
|
|
* not to optimize for aborts. Note that heap_xlog_update must be kept in
|
|
* sync if this decision changes.
|
|
*/
|
|
PageSetPrunable(page, xid);
|
|
|
|
if (use_hot_update)
|
|
{
|
|
/* Mark the old tuple as HOT-updated */
|
|
HeapTupleSetHotUpdated(&oldtup);
|
|
/* And mark the new tuple as heap-only */
|
|
HeapTupleSetHeapOnly(heaptup);
|
|
/* Mark the caller's copy too, in case different from heaptup */
|
|
HeapTupleSetHeapOnly(newtup);
|
|
}
|
|
else
|
|
{
|
|
/* Make sure tuples are correctly marked as not-HOT */
|
|
HeapTupleClearHotUpdated(&oldtup);
|
|
HeapTupleClearHeapOnly(heaptup);
|
|
HeapTupleClearHeapOnly(newtup);
|
|
}
|
|
|
|
RelationPutHeapTuple(relation, newbuf, heaptup, false); /* insert new tuple */
|
|
|
|
|
|
/* Clear obsolete visibility flags, possibly set by ourselves above... */
|
|
oldtup.t_data->t_infomask &= ~(HEAP_XMAX_BITS | HEAP_MOVED);
|
|
oldtup.t_data->t_infomask2 &= ~HEAP_KEYS_UPDATED;
|
|
/* ... and store info about transaction updating this tuple */
|
|
Assert(TransactionIdIsValid(xmax_old_tuple));
|
|
HeapTupleHeaderSetXmax(oldtup.t_data, xmax_old_tuple);
|
|
oldtup.t_data->t_infomask |= infomask_old_tuple;
|
|
oldtup.t_data->t_infomask2 |= infomask2_old_tuple;
|
|
HeapTupleHeaderSetCmax(oldtup.t_data, cid, iscombo);
|
|
|
|
/* record address of new tuple in t_ctid of old one */
|
|
oldtup.t_data->t_ctid = heaptup->t_self;
|
|
|
|
/* clear PD_ALL_VISIBLE flags, reset all visibilitymap bits */
|
|
if (PageIsAllVisible(BufferGetPage(buffer)))
|
|
{
|
|
all_visible_cleared = true;
|
|
PageClearAllVisible(BufferGetPage(buffer));
|
|
visibilitymap_clear(relation, BufferGetBlockNumber(buffer),
|
|
vmbuffer, VISIBILITYMAP_VALID_BITS);
|
|
}
|
|
if (newbuf != buffer && PageIsAllVisible(BufferGetPage(newbuf)))
|
|
{
|
|
all_visible_cleared_new = true;
|
|
PageClearAllVisible(BufferGetPage(newbuf));
|
|
visibilitymap_clear(relation, BufferGetBlockNumber(newbuf),
|
|
vmbuffer_new, VISIBILITYMAP_VALID_BITS);
|
|
}
|
|
|
|
if (newbuf != buffer)
|
|
MarkBufferDirty(newbuf);
|
|
MarkBufferDirty(buffer);
|
|
|
|
/* XLOG stuff */
|
|
if (RelationNeedsWAL(relation))
|
|
{
|
|
XLogRecPtr recptr;
|
|
|
|
/*
|
|
* For logical decoding we need combocids to properly decode the
|
|
* catalog.
|
|
*/
|
|
if (RelationIsAccessibleInLogicalDecoding(relation))
|
|
{
|
|
log_heap_new_cid(relation, &oldtup);
|
|
log_heap_new_cid(relation, heaptup);
|
|
}
|
|
|
|
recptr = log_heap_update(relation, buffer,
|
|
newbuf, &oldtup, heaptup,
|
|
old_key_tuple,
|
|
all_visible_cleared,
|
|
all_visible_cleared_new);
|
|
if (newbuf != buffer)
|
|
{
|
|
PageSetLSN(BufferGetPage(newbuf), recptr);
|
|
}
|
|
PageSetLSN(BufferGetPage(buffer), recptr);
|
|
}
|
|
|
|
END_CRIT_SECTION();
|
|
|
|
if (newbuf != buffer)
|
|
LockBuffer(newbuf, BUFFER_LOCK_UNLOCK);
|
|
LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
|
|
|
|
/*
|
|
* Mark old tuple for invalidation from system caches at next command
|
|
* boundary, and mark the new tuple for invalidation in case we abort. We
|
|
* have to do this before releasing the buffer because oldtup is in the
|
|
* buffer. (heaptup is all in local memory, but it's necessary to process
|
|
* both tuple versions in one call to inval.c so we can avoid redundant
|
|
* sinval messages.)
|
|
*/
|
|
CacheInvalidateHeapTuple(relation, &oldtup, heaptup);
|
|
|
|
/* Now we can release the buffer(s) */
|
|
if (newbuf != buffer)
|
|
ReleaseBuffer(newbuf);
|
|
ReleaseBuffer(buffer);
|
|
if (BufferIsValid(vmbuffer_new))
|
|
ReleaseBuffer(vmbuffer_new);
|
|
if (BufferIsValid(vmbuffer))
|
|
ReleaseBuffer(vmbuffer);
|
|
|
|
/*
|
|
* Release the lmgr tuple lock, if we had it.
|
|
*/
|
|
if (have_tuple_lock)
|
|
UnlockTupleTuplock(relation, &(oldtup.t_self), *lockmode);
|
|
|
|
pgstat_count_heap_update(relation, use_hot_update);
|
|
|
|
/*
|
|
* If heaptup is a private copy, release it. Don't forget to copy t_self
|
|
* back to the caller's image, too.
|
|
*/
|
|
if (heaptup != newtup)
|
|
{
|
|
newtup->t_self = heaptup->t_self;
|
|
heap_freetuple(heaptup);
|
|
}
|
|
|
|
if (old_key_tuple != NULL && old_key_copied)
|
|
heap_freetuple(old_key_tuple);
|
|
|
|
bms_free(hot_attrs);
|
|
bms_free(key_attrs);
|
|
bms_free(id_attrs);
|
|
bms_free(modified_attrs);
|
|
bms_free(interesting_attrs);
|
|
|
|
return HeapTupleMayBeUpdated;
|
|
}
|
|
|
|
/*
|
|
* Check if the specified attribute's value is same in both given tuples.
|
|
* Subroutine for HeapDetermineModifiedColumns.
|
|
*/
|
|
static bool
|
|
heap_tuple_attr_equals(TupleDesc tupdesc, int attrnum,
|
|
HeapTuple tup1, HeapTuple tup2)
|
|
{
|
|
Datum value1,
|
|
value2;
|
|
bool isnull1,
|
|
isnull2;
|
|
Form_pg_attribute att;
|
|
|
|
/*
|
|
* If it's a whole-tuple reference, say "not equal". It's not really
|
|
* worth supporting this case, since it could only succeed after a no-op
|
|
* update, which is hardly a case worth optimizing for.
|
|
*/
|
|
if (attrnum == 0)
|
|
return false;
|
|
|
|
/*
|
|
* Likewise, automatically say "not equal" for any system attribute other
|
|
* than OID and tableOID; we cannot expect these to be consistent in a HOT
|
|
* chain, or even to be set correctly yet in the new tuple.
|
|
*/
|
|
if (attrnum < 0)
|
|
{
|
|
if (attrnum != ObjectIdAttributeNumber &&
|
|
attrnum != TableOidAttributeNumber)
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* Extract the corresponding values. XXX this is pretty inefficient if
|
|
* there are many indexed columns. Should HeapDetermineModifiedColumns do
|
|
* a single heap_deform_tuple call on each tuple, instead? But that
|
|
* doesn't work for system columns ...
|
|
*/
|
|
value1 = heap_getattr(tup1, attrnum, tupdesc, &isnull1);
|
|
value2 = heap_getattr(tup2, attrnum, tupdesc, &isnull2);
|
|
|
|
/*
|
|
* If one value is NULL and other is not, then they are certainly not
|
|
* equal
|
|
*/
|
|
if (isnull1 != isnull2)
|
|
return false;
|
|
|
|
/*
|
|
* If both are NULL, they can be considered equal.
|
|
*/
|
|
if (isnull1)
|
|
return true;
|
|
|
|
/*
|
|
* We do simple binary comparison of the two datums. This may be overly
|
|
* strict because there can be multiple binary representations for the
|
|
* same logical value. But we should be OK as long as there are no false
|
|
* positives. Using a type-specific equality operator is messy because
|
|
* there could be multiple notions of equality in different operator
|
|
* classes; furthermore, we cannot safely invoke user-defined functions
|
|
* while holding exclusive buffer lock.
|
|
*/
|
|
if (attrnum <= 0)
|
|
{
|
|
/* The only allowed system columns are OIDs, so do this */
|
|
return (DatumGetObjectId(value1) == DatumGetObjectId(value2));
|
|
}
|
|
else
|
|
{
|
|
Assert(attrnum <= tupdesc->natts);
|
|
att = TupleDescAttr(tupdesc, attrnum - 1);
|
|
return datumIsEqual(value1, value2, att->attbyval, att->attlen);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Check which columns are being updated.
|
|
*
|
|
* Given an updated tuple, determine (and return into the output bitmapset),
|
|
* from those listed as interesting, the set of columns that changed.
|
|
*
|
|
* The input bitmapset is destructively modified; that is OK since this is
|
|
* invoked at most once in heap_update.
|
|
*/
|
|
static Bitmapset *
|
|
HeapDetermineModifiedColumns(Relation relation, Bitmapset *interesting_cols,
|
|
HeapTuple oldtup, HeapTuple newtup)
|
|
{
|
|
int attnum;
|
|
Bitmapset *modified = NULL;
|
|
|
|
while ((attnum = bms_first_member(interesting_cols)) >= 0)
|
|
{
|
|
attnum += FirstLowInvalidHeapAttributeNumber;
|
|
|
|
if (!heap_tuple_attr_equals(RelationGetDescr(relation),
|
|
attnum, oldtup, newtup))
|
|
modified = bms_add_member(modified,
|
|
attnum - FirstLowInvalidHeapAttributeNumber);
|
|
}
|
|
|
|
return modified;
|
|
}
|
|
|
|
/*
|
|
* simple_heap_update - replace a tuple
|
|
*
|
|
* This routine may be used to update a tuple when concurrent updates of
|
|
* the target tuple are not expected (for example, because we have a lock
|
|
* on the relation associated with the tuple). Any failure is reported
|
|
* via ereport().
|
|
*/
|
|
void
|
|
simple_heap_update(Relation relation, ItemPointer otid, HeapTuple tup)
|
|
{
|
|
HTSU_Result result;
|
|
HeapUpdateFailureData hufd;
|
|
LockTupleMode lockmode;
|
|
|
|
result = heap_update(relation, otid, tup,
|
|
GetCurrentCommandId(true), InvalidSnapshot,
|
|
true /* wait for commit */ ,
|
|
&hufd, &lockmode);
|
|
switch (result)
|
|
{
|
|
case HeapTupleSelfUpdated:
|
|
/* Tuple was already updated in current command? */
|
|
elog(ERROR, "tuple already updated by self");
|
|
break;
|
|
|
|
case HeapTupleMayBeUpdated:
|
|
/* done successfully */
|
|
break;
|
|
|
|
case HeapTupleUpdated:
|
|
elog(ERROR, "tuple concurrently updated");
|
|
break;
|
|
|
|
default:
|
|
elog(ERROR, "unrecognized heap_update status: %u", result);
|
|
break;
|
|
}
|
|
}
|
|
|
|
|
|
/*
|
|
* Return the MultiXactStatus corresponding to the given tuple lock mode.
|
|
*/
|
|
static MultiXactStatus
|
|
get_mxact_status_for_lock(LockTupleMode mode, bool is_update)
|
|
{
|
|
int retval;
|
|
|
|
if (is_update)
|
|
retval = tupleLockExtraInfo[mode].updstatus;
|
|
else
|
|
retval = tupleLockExtraInfo[mode].lockstatus;
|
|
|
|
if (retval == -1)
|
|
elog(ERROR, "invalid lock tuple mode %d/%s", mode,
|
|
is_update ? "true" : "false");
|
|
|
|
return (MultiXactStatus) retval;
|
|
}
|
|
|
|
/*
|
|
* heap_lock_tuple - lock a tuple in shared or exclusive mode
|
|
*
|
|
* Note that this acquires a buffer pin, which the caller must release.
|
|
*
|
|
* Input parameters:
|
|
* relation: relation containing tuple (caller must hold suitable lock)
|
|
* tuple->t_self: TID of tuple to lock (rest of struct need not be valid)
|
|
* cid: current command ID (used for visibility test, and stored into
|
|
* tuple's cmax if lock is successful)
|
|
* mode: indicates if shared or exclusive tuple lock is desired
|
|
* wait_policy: what to do if tuple lock is not available
|
|
* follow_updates: if true, follow the update chain to also lock descendant
|
|
* tuples.
|
|
*
|
|
* Output parameters:
|
|
* *tuple: all fields filled in
|
|
* *buffer: set to buffer holding tuple (pinned but not locked at exit)
|
|
* *hufd: filled in failure cases (see below)
|
|
*
|
|
* Function result may be:
|
|
* HeapTupleMayBeUpdated: lock was successfully acquired
|
|
* HeapTupleInvisible: lock failed because tuple was never visible to us
|
|
* HeapTupleSelfUpdated: lock failed because tuple updated by self
|
|
* HeapTupleUpdated: lock failed because tuple updated by other xact
|
|
* HeapTupleWouldBlock: lock couldn't be acquired and wait_policy is skip
|
|
*
|
|
* In the failure cases other than HeapTupleInvisible, the routine fills
|
|
* *hufd with the tuple's t_ctid, t_xmax (resolving a possible MultiXact,
|
|
* if necessary), and t_cmax (the last only for HeapTupleSelfUpdated,
|
|
* since we cannot obtain cmax from a combocid generated by another
|
|
* transaction).
|
|
* See comments for struct HeapUpdateFailureData for additional info.
|
|
*
|
|
* See README.tuplock for a thorough explanation of this mechanism.
|
|
*/
|
|
HTSU_Result
|
|
heap_lock_tuple(Relation relation, HeapTuple tuple,
|
|
CommandId cid, LockTupleMode mode, LockWaitPolicy wait_policy,
|
|
bool follow_updates,
|
|
Buffer *buffer, HeapUpdateFailureData *hufd)
|
|
{
|
|
HTSU_Result result;
|
|
ItemPointer tid = &(tuple->t_self);
|
|
ItemId lp;
|
|
Page page;
|
|
Buffer vmbuffer = InvalidBuffer;
|
|
BlockNumber block;
|
|
TransactionId xid,
|
|
xmax;
|
|
uint16 old_infomask,
|
|
new_infomask,
|
|
new_infomask2;
|
|
bool first_time = true;
|
|
bool have_tuple_lock = false;
|
|
bool cleared_all_frozen = false;
|
|
|
|
*buffer = ReadBuffer(relation, ItemPointerGetBlockNumber(tid));
|
|
block = ItemPointerGetBlockNumber(tid);
|
|
|
|
/*
|
|
* Before locking the buffer, pin the visibility map page if it appears to
|
|
* be necessary. Since we haven't got the lock yet, someone else might be
|
|
* in the middle of changing this, so we'll need to recheck after we have
|
|
* the lock.
|
|
*/
|
|
if (PageIsAllVisible(BufferGetPage(*buffer)))
|
|
visibilitymap_pin(relation, block, &vmbuffer);
|
|
|
|
LockBuffer(*buffer, BUFFER_LOCK_EXCLUSIVE);
|
|
|
|
page = BufferGetPage(*buffer);
|
|
lp = PageGetItemId(page, ItemPointerGetOffsetNumber(tid));
|
|
Assert(ItemIdIsNormal(lp));
|
|
|
|
tuple->t_data = (HeapTupleHeader) PageGetItem(page, lp);
|
|
tuple->t_len = ItemIdGetLength(lp);
|
|
tuple->t_tableOid = RelationGetRelid(relation);
|
|
|
|
l3:
|
|
result = HeapTupleSatisfiesUpdate(tuple, cid, *buffer);
|
|
|
|
if (result == HeapTupleInvisible)
|
|
{
|
|
/*
|
|
* This is possible, but only when locking a tuple for ON CONFLICT
|
|
* UPDATE. We return this value here rather than throwing an error in
|
|
* order to give that case the opportunity to throw a more specific
|
|
* error.
|
|
*/
|
|
result = HeapTupleInvisible;
|
|
goto out_locked;
|
|
}
|
|
else if (result == HeapTupleBeingUpdated || result == HeapTupleUpdated)
|
|
{
|
|
TransactionId xwait;
|
|
uint16 infomask;
|
|
uint16 infomask2;
|
|
bool require_sleep;
|
|
ItemPointerData t_ctid;
|
|
|
|
/* must copy state data before unlocking buffer */
|
|
xwait = HeapTupleHeaderGetRawXmax(tuple->t_data);
|
|
infomask = tuple->t_data->t_infomask;
|
|
infomask2 = tuple->t_data->t_infomask2;
|
|
ItemPointerCopy(&tuple->t_data->t_ctid, &t_ctid);
|
|
|
|
LockBuffer(*buffer, BUFFER_LOCK_UNLOCK);
|
|
|
|
/*
|
|
* If any subtransaction of the current top transaction already holds
|
|
* a lock as strong as or stronger than what we're requesting, we
|
|
* effectively hold the desired lock already. We *must* succeed
|
|
* without trying to take the tuple lock, else we will deadlock
|
|
* against anyone wanting to acquire a stronger lock.
|
|
*
|
|
* Note we only do this the first time we loop on the HTSU result;
|
|
* there is no point in testing in subsequent passes, because
|
|
* evidently our own transaction cannot have acquired a new lock after
|
|
* the first time we checked.
|
|
*/
|
|
if (first_time)
|
|
{
|
|
first_time = false;
|
|
|
|
if (infomask & HEAP_XMAX_IS_MULTI)
|
|
{
|
|
int i;
|
|
int nmembers;
|
|
MultiXactMember *members;
|
|
|
|
/*
|
|
* We don't need to allow old multixacts here; if that had
|
|
* been the case, HeapTupleSatisfiesUpdate would have returned
|
|
* MayBeUpdated and we wouldn't be here.
|
|
*/
|
|
nmembers =
|
|
GetMultiXactIdMembers(xwait, &members, false,
|
|
HEAP_XMAX_IS_LOCKED_ONLY(infomask));
|
|
|
|
for (i = 0; i < nmembers; i++)
|
|
{
|
|
/* only consider members of our own transaction */
|
|
if (!TransactionIdIsCurrentTransactionId(members[i].xid))
|
|
continue;
|
|
|
|
if (TUPLOCK_from_mxstatus(members[i].status) >= mode)
|
|
{
|
|
pfree(members);
|
|
result = HeapTupleMayBeUpdated;
|
|
goto out_unlocked;
|
|
}
|
|
}
|
|
|
|
if (members)
|
|
pfree(members);
|
|
}
|
|
else if (TransactionIdIsCurrentTransactionId(xwait))
|
|
{
|
|
switch (mode)
|
|
{
|
|
case LockTupleKeyShare:
|
|
Assert(HEAP_XMAX_IS_KEYSHR_LOCKED(infomask) ||
|
|
HEAP_XMAX_IS_SHR_LOCKED(infomask) ||
|
|
HEAP_XMAX_IS_EXCL_LOCKED(infomask));
|
|
result = HeapTupleMayBeUpdated;
|
|
goto out_unlocked;
|
|
case LockTupleShare:
|
|
if (HEAP_XMAX_IS_SHR_LOCKED(infomask) ||
|
|
HEAP_XMAX_IS_EXCL_LOCKED(infomask))
|
|
{
|
|
result = HeapTupleMayBeUpdated;
|
|
goto out_unlocked;
|
|
}
|
|
break;
|
|
case LockTupleNoKeyExclusive:
|
|
if (HEAP_XMAX_IS_EXCL_LOCKED(infomask))
|
|
{
|
|
result = HeapTupleMayBeUpdated;
|
|
goto out_unlocked;
|
|
}
|
|
break;
|
|
case LockTupleExclusive:
|
|
if (HEAP_XMAX_IS_EXCL_LOCKED(infomask) &&
|
|
infomask2 & HEAP_KEYS_UPDATED)
|
|
{
|
|
result = HeapTupleMayBeUpdated;
|
|
goto out_unlocked;
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Initially assume that we will have to wait for the locking
|
|
* transaction(s) to finish. We check various cases below in which
|
|
* this can be turned off.
|
|
*/
|
|
require_sleep = true;
|
|
if (mode == LockTupleKeyShare)
|
|
{
|
|
/*
|
|
* If we're requesting KeyShare, and there's no update present, we
|
|
* don't need to wait. Even if there is an update, we can still
|
|
* continue if the key hasn't been modified.
|
|
*
|
|
* However, if there are updates, we need to walk the update chain
|
|
* to mark future versions of the row as locked, too. That way,
|
|
* if somebody deletes that future version, we're protected
|
|
* against the key going away. This locking of future versions
|
|
* could block momentarily, if a concurrent transaction is
|
|
* deleting a key; or it could return a value to the effect that
|
|
* the transaction deleting the key has already committed. So we
|
|
* do this before re-locking the buffer; otherwise this would be
|
|
* prone to deadlocks.
|
|
*
|
|
* Note that the TID we're locking was grabbed before we unlocked
|
|
* the buffer. For it to change while we're not looking, the
|
|
* other properties we're testing for below after re-locking the
|
|
* buffer would also change, in which case we would restart this
|
|
* loop above.
|
|
*/
|
|
if (!(infomask2 & HEAP_KEYS_UPDATED))
|
|
{
|
|
bool updated;
|
|
|
|
updated = !HEAP_XMAX_IS_LOCKED_ONLY(infomask);
|
|
|
|
/*
|
|
* If there are updates, follow the update chain; bail out if
|
|
* that cannot be done.
|
|
*/
|
|
if (follow_updates && updated)
|
|
{
|
|
HTSU_Result res;
|
|
|
|
res = heap_lock_updated_tuple(relation, tuple, &t_ctid,
|
|
GetCurrentTransactionId(),
|
|
mode);
|
|
if (res != HeapTupleMayBeUpdated)
|
|
{
|
|
result = res;
|
|
/* recovery code expects to have buffer lock held */
|
|
LockBuffer(*buffer, BUFFER_LOCK_EXCLUSIVE);
|
|
goto failed;
|
|
}
|
|
}
|
|
|
|
LockBuffer(*buffer, BUFFER_LOCK_EXCLUSIVE);
|
|
|
|
/*
|
|
* Make sure it's still an appropriate lock, else start over.
|
|
* Also, if it wasn't updated before we released the lock, but
|
|
* is updated now, we start over too; the reason is that we
|
|
* now need to follow the update chain to lock the new
|
|
* versions.
|
|
*/
|
|
if (!HeapTupleHeaderIsOnlyLocked(tuple->t_data) &&
|
|
((tuple->t_data->t_infomask2 & HEAP_KEYS_UPDATED) ||
|
|
!updated))
|
|
goto l3;
|
|
|
|
/* Things look okay, so we can skip sleeping */
|
|
require_sleep = false;
|
|
|
|
/*
|
|
* Note we allow Xmax to change here; other updaters/lockers
|
|
* could have modified it before we grabbed the buffer lock.
|
|
* However, this is not a problem, because with the recheck we
|
|
* just did we ensure that they still don't conflict with the
|
|
* lock we want.
|
|
*/
|
|
}
|
|
}
|
|
else if (mode == LockTupleShare)
|
|
{
|
|
/*
|
|
* If we're requesting Share, we can similarly avoid sleeping if
|
|
* there's no update and no exclusive lock present.
|
|
*/
|
|
if (HEAP_XMAX_IS_LOCKED_ONLY(infomask) &&
|
|
!HEAP_XMAX_IS_EXCL_LOCKED(infomask))
|
|
{
|
|
LockBuffer(*buffer, BUFFER_LOCK_EXCLUSIVE);
|
|
|
|
/*
|
|
* Make sure it's still an appropriate lock, else start over.
|
|
* See above about allowing xmax to change.
|
|
*/
|
|
if (!HEAP_XMAX_IS_LOCKED_ONLY(tuple->t_data->t_infomask) ||
|
|
HEAP_XMAX_IS_EXCL_LOCKED(tuple->t_data->t_infomask))
|
|
goto l3;
|
|
require_sleep = false;
|
|
}
|
|
}
|
|
else if (mode == LockTupleNoKeyExclusive)
|
|
{
|
|
/*
|
|
* If we're requesting NoKeyExclusive, we might also be able to
|
|
* avoid sleeping; just ensure that there no conflicting lock
|
|
* already acquired.
|
|
*/
|
|
if (infomask & HEAP_XMAX_IS_MULTI)
|
|
{
|
|
if (!DoesMultiXactIdConflict((MultiXactId) xwait, infomask,
|
|
mode))
|
|
{
|
|
/*
|
|
* No conflict, but if the xmax changed under us in the
|
|
* meantime, start over.
|
|
*/
|
|
LockBuffer(*buffer, BUFFER_LOCK_EXCLUSIVE);
|
|
if (xmax_infomask_changed(tuple->t_data->t_infomask, infomask) ||
|
|
!TransactionIdEquals(HeapTupleHeaderGetRawXmax(tuple->t_data),
|
|
xwait))
|
|
goto l3;
|
|
|
|
/* otherwise, we're good */
|
|
require_sleep = false;
|
|
}
|
|
}
|
|
else if (HEAP_XMAX_IS_KEYSHR_LOCKED(infomask))
|
|
{
|
|
LockBuffer(*buffer, BUFFER_LOCK_EXCLUSIVE);
|
|
|
|
/* if the xmax changed in the meantime, start over */
|
|
if (xmax_infomask_changed(tuple->t_data->t_infomask, infomask) ||
|
|
!TransactionIdEquals(
|
|
HeapTupleHeaderGetRawXmax(tuple->t_data),
|
|
xwait))
|
|
goto l3;
|
|
/* otherwise, we're good */
|
|
require_sleep = false;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* As a check independent from those above, we can also avoid sleeping
|
|
* if the current transaction is the sole locker of the tuple. Note
|
|
* that the strength of the lock already held is irrelevant; this is
|
|
* not about recording the lock in Xmax (which will be done regardless
|
|
* of this optimization, below). Also, note that the cases where we
|
|
* hold a lock stronger than we are requesting are already handled
|
|
* above by not doing anything.
|
|
*
|
|
* Note we only deal with the non-multixact case here; MultiXactIdWait
|
|
* is well equipped to deal with this situation on its own.
|
|
*/
|
|
if (require_sleep && !(infomask & HEAP_XMAX_IS_MULTI) &&
|
|
TransactionIdIsCurrentTransactionId(xwait))
|
|
{
|
|
/* ... but if the xmax changed in the meantime, start over */
|
|
LockBuffer(*buffer, BUFFER_LOCK_EXCLUSIVE);
|
|
if (xmax_infomask_changed(tuple->t_data->t_infomask, infomask) ||
|
|
!TransactionIdEquals(HeapTupleHeaderGetRawXmax(tuple->t_data),
|
|
xwait))
|
|
goto l3;
|
|
Assert(HEAP_XMAX_IS_LOCKED_ONLY(tuple->t_data->t_infomask));
|
|
require_sleep = false;
|
|
}
|
|
|
|
/*
|
|
* Time to sleep on the other transaction/multixact, if necessary.
|
|
*
|
|
* If the other transaction is an update that's already committed,
|
|
* then sleeping cannot possibly do any good: if we're required to
|
|
* sleep, get out to raise an error instead.
|
|
*
|
|
* By here, we either have already acquired the buffer exclusive lock,
|
|
* or we must wait for the locking transaction or multixact; so below
|
|
* we ensure that we grab buffer lock after the sleep.
|
|
*/
|
|
if (require_sleep && result == HeapTupleUpdated)
|
|
{
|
|
LockBuffer(*buffer, BUFFER_LOCK_EXCLUSIVE);
|
|
goto failed;
|
|
}
|
|
else if (require_sleep)
|
|
{
|
|
/*
|
|
* Acquire tuple lock to establish our priority for the tuple, or
|
|
* die trying. LockTuple will release us when we are next-in-line
|
|
* for the tuple. We must do this even if we are share-locking.
|
|
*
|
|
* If we are forced to "start over" below, we keep the tuple lock;
|
|
* this arranges that we stay at the head of the line while
|
|
* rechecking tuple state.
|
|
*/
|
|
if (!heap_acquire_tuplock(relation, tid, mode, wait_policy,
|
|
&have_tuple_lock))
|
|
{
|
|
/*
|
|
* This can only happen if wait_policy is Skip and the lock
|
|
* couldn't be obtained.
|
|
*/
|
|
result = HeapTupleWouldBlock;
|
|
/* recovery code expects to have buffer lock held */
|
|
LockBuffer(*buffer, BUFFER_LOCK_EXCLUSIVE);
|
|
goto failed;
|
|
}
|
|
|
|
if (infomask & HEAP_XMAX_IS_MULTI)
|
|
{
|
|
MultiXactStatus status = get_mxact_status_for_lock(mode, false);
|
|
|
|
/* We only ever lock tuples, never update them */
|
|
if (status >= MultiXactStatusNoKeyUpdate)
|
|
elog(ERROR, "invalid lock mode in heap_lock_tuple");
|
|
|
|
/* wait for multixact to end, or die trying */
|
|
switch (wait_policy)
|
|
{
|
|
case LockWaitBlock:
|
|
MultiXactIdWait((MultiXactId) xwait, status, infomask,
|
|
relation, &tuple->t_self, XLTW_Lock, NULL);
|
|
break;
|
|
case LockWaitSkip:
|
|
if (!ConditionalMultiXactIdWait((MultiXactId) xwait,
|
|
status, infomask, relation,
|
|
NULL))
|
|
{
|
|
result = HeapTupleWouldBlock;
|
|
/* recovery code expects to have buffer lock held */
|
|
LockBuffer(*buffer, BUFFER_LOCK_EXCLUSIVE);
|
|
goto failed;
|
|
}
|
|
break;
|
|
case LockWaitError:
|
|
if (!ConditionalMultiXactIdWait((MultiXactId) xwait,
|
|
status, infomask, relation,
|
|
NULL))
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_LOCK_NOT_AVAILABLE),
|
|
errmsg("could not obtain lock on row in relation \"%s\"",
|
|
RelationGetRelationName(relation))));
|
|
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* Of course, the multixact might not be done here: if we're
|
|
* requesting a light lock mode, other transactions with light
|
|
* locks could still be alive, as well as locks owned by our
|
|
* own xact or other subxacts of this backend. We need to
|
|
* preserve the surviving MultiXact members. Note that it
|
|
* isn't absolutely necessary in the latter case, but doing so
|
|
* is simpler.
|
|
*/
|
|
}
|
|
else
|
|
{
|
|
/* wait for regular transaction to end, or die trying */
|
|
switch (wait_policy)
|
|
{
|
|
case LockWaitBlock:
|
|
XactLockTableWait(xwait, relation, &tuple->t_self,
|
|
XLTW_Lock);
|
|
break;
|
|
case LockWaitSkip:
|
|
if (!ConditionalXactLockTableWait(xwait))
|
|
{
|
|
result = HeapTupleWouldBlock;
|
|
/* recovery code expects to have buffer lock held */
|
|
LockBuffer(*buffer, BUFFER_LOCK_EXCLUSIVE);
|
|
goto failed;
|
|
}
|
|
break;
|
|
case LockWaitError:
|
|
if (!ConditionalXactLockTableWait(xwait))
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_LOCK_NOT_AVAILABLE),
|
|
errmsg("could not obtain lock on row in relation \"%s\"",
|
|
RelationGetRelationName(relation))));
|
|
break;
|
|
}
|
|
}
|
|
|
|
/* if there are updates, follow the update chain */
|
|
if (follow_updates && !HEAP_XMAX_IS_LOCKED_ONLY(infomask))
|
|
{
|
|
HTSU_Result res;
|
|
|
|
res = heap_lock_updated_tuple(relation, tuple, &t_ctid,
|
|
GetCurrentTransactionId(),
|
|
mode);
|
|
if (res != HeapTupleMayBeUpdated)
|
|
{
|
|
result = res;
|
|
/* recovery code expects to have buffer lock held */
|
|
LockBuffer(*buffer, BUFFER_LOCK_EXCLUSIVE);
|
|
goto failed;
|
|
}
|
|
}
|
|
|
|
LockBuffer(*buffer, BUFFER_LOCK_EXCLUSIVE);
|
|
|
|
/*
|
|
* xwait is done, but if xwait had just locked the tuple then some
|
|
* other xact could update this tuple before we get to this point.
|
|
* Check for xmax change, and start over if so.
|
|
*/
|
|
if (xmax_infomask_changed(tuple->t_data->t_infomask, infomask) ||
|
|
!TransactionIdEquals(HeapTupleHeaderGetRawXmax(tuple->t_data),
|
|
xwait))
|
|
goto l3;
|
|
|
|
if (!(infomask & HEAP_XMAX_IS_MULTI))
|
|
{
|
|
/*
|
|
* Otherwise check if it committed or aborted. Note we cannot
|
|
* be here if the tuple was only locked by somebody who didn't
|
|
* conflict with us; that would have been handled above. So
|
|
* that transaction must necessarily be gone by now. But
|
|
* don't check for this in the multixact case, because some
|
|
* locker transactions might still be running.
|
|
*/
|
|
UpdateXmaxHintBits(tuple->t_data, *buffer, xwait);
|
|
}
|
|
}
|
|
|
|
/* By here, we're certain that we hold buffer exclusive lock again */
|
|
|
|
/*
|
|
* We may lock if previous xmax aborted, or if it committed but only
|
|
* locked the tuple without updating it; or if we didn't have to wait
|
|
* at all for whatever reason.
|
|
*/
|
|
if (!require_sleep ||
|
|
(tuple->t_data->t_infomask & HEAP_XMAX_INVALID) ||
|
|
HEAP_XMAX_IS_LOCKED_ONLY(tuple->t_data->t_infomask) ||
|
|
HeapTupleHeaderIsOnlyLocked(tuple->t_data))
|
|
result = HeapTupleMayBeUpdated;
|
|
else
|
|
result = HeapTupleUpdated;
|
|
}
|
|
|
|
failed:
|
|
if (result != HeapTupleMayBeUpdated)
|
|
{
|
|
Assert(result == HeapTupleSelfUpdated || result == HeapTupleUpdated ||
|
|
result == HeapTupleWouldBlock);
|
|
Assert(!(tuple->t_data->t_infomask & HEAP_XMAX_INVALID));
|
|
hufd->ctid = tuple->t_data->t_ctid;
|
|
hufd->xmax = HeapTupleHeaderGetUpdateXid(tuple->t_data);
|
|
if (result == HeapTupleSelfUpdated)
|
|
hufd->cmax = HeapTupleHeaderGetCmax(tuple->t_data);
|
|
else
|
|
hufd->cmax = InvalidCommandId;
|
|
goto out_locked;
|
|
}
|
|
|
|
/*
|
|
* If we didn't pin the visibility map page and the page has become all
|
|
* visible while we were busy locking the buffer, or during some
|
|
* subsequent window during which we had it unlocked, we'll have to unlock
|
|
* and re-lock, to avoid holding the buffer lock across I/O. That's a bit
|
|
* unfortunate, especially since we'll now have to recheck whether the
|
|
* tuple has been locked or updated under us, but hopefully it won't
|
|
* happen very often.
|
|
*/
|
|
if (vmbuffer == InvalidBuffer && PageIsAllVisible(page))
|
|
{
|
|
LockBuffer(*buffer, BUFFER_LOCK_UNLOCK);
|
|
visibilitymap_pin(relation, block, &vmbuffer);
|
|
LockBuffer(*buffer, BUFFER_LOCK_EXCLUSIVE);
|
|
goto l3;
|
|
}
|
|
|
|
xmax = HeapTupleHeaderGetRawXmax(tuple->t_data);
|
|
old_infomask = tuple->t_data->t_infomask;
|
|
|
|
/*
|
|
* If this is the first possibly-multixact-able operation in the current
|
|
* transaction, set my per-backend OldestMemberMXactId setting. We can be
|
|
* certain that the transaction will never become a member of any older
|
|
* MultiXactIds than that. (We have to do this even if we end up just
|
|
* using our own TransactionId below, since some other backend could
|
|
* incorporate our XID into a MultiXact immediately afterwards.)
|
|
*/
|
|
MultiXactIdSetOldestMember();
|
|
|
|
/*
|
|
* Compute the new xmax and infomask to store into the tuple. Note we do
|
|
* not modify the tuple just yet, because that would leave it in the wrong
|
|
* state if multixact.c elogs.
|
|
*/
|
|
compute_new_xmax_infomask(xmax, old_infomask, tuple->t_data->t_infomask2,
|
|
GetCurrentTransactionId(), mode, false,
|
|
&xid, &new_infomask, &new_infomask2);
|
|
|
|
START_CRIT_SECTION();
|
|
|
|
/*
|
|
* Store transaction information of xact locking the tuple.
|
|
*
|
|
* Note: Cmax is meaningless in this context, so don't set it; this avoids
|
|
* possibly generating a useless combo CID. Moreover, if we're locking a
|
|
* previously updated tuple, it's important to preserve the Cmax.
|
|
*
|
|
* Also reset the HOT UPDATE bit, but only if there's no update; otherwise
|
|
* we would break the HOT chain.
|
|
*/
|
|
tuple->t_data->t_infomask &= ~HEAP_XMAX_BITS;
|
|
tuple->t_data->t_infomask2 &= ~HEAP_KEYS_UPDATED;
|
|
tuple->t_data->t_infomask |= new_infomask;
|
|
tuple->t_data->t_infomask2 |= new_infomask2;
|
|
if (HEAP_XMAX_IS_LOCKED_ONLY(new_infomask))
|
|
HeapTupleHeaderClearHotUpdated(tuple->t_data);
|
|
HeapTupleHeaderSetXmax(tuple->t_data, xid);
|
|
|
|
/*
|
|
* Make sure there is no forward chain link in t_ctid. Note that in the
|
|
* cases where the tuple has been updated, we must not overwrite t_ctid,
|
|
* because it was set by the updater. Moreover, if the tuple has been
|
|
* updated, we need to follow the update chain to lock the new versions of
|
|
* the tuple as well.
|
|
*/
|
|
if (HEAP_XMAX_IS_LOCKED_ONLY(new_infomask))
|
|
tuple->t_data->t_ctid = *tid;
|
|
|
|
/* Clear only the all-frozen bit on visibility map if needed */
|
|
if (PageIsAllVisible(page) &&
|
|
visibilitymap_clear(relation, block, vmbuffer,
|
|
VISIBILITYMAP_ALL_FROZEN))
|
|
cleared_all_frozen = true;
|
|
|
|
|
|
MarkBufferDirty(*buffer);
|
|
|
|
/*
|
|
* XLOG stuff. You might think that we don't need an XLOG record because
|
|
* there is no state change worth restoring after a crash. You would be
|
|
* wrong however: we have just written either a TransactionId or a
|
|
* MultiXactId that may never have been seen on disk before, and we need
|
|
* to make sure that there are XLOG entries covering those ID numbers.
|
|
* Else the same IDs might be re-used after a crash, which would be
|
|
* disastrous if this page made it to disk before the crash. Essentially
|
|
* we have to enforce the WAL log-before-data rule even in this case.
|
|
* (Also, in a PITR log-shipping or 2PC environment, we have to have XLOG
|
|
* entries for everything anyway.)
|
|
*/
|
|
if (RelationNeedsWAL(relation))
|
|
{
|
|
xl_heap_lock xlrec;
|
|
XLogRecPtr recptr;
|
|
|
|
XLogBeginInsert();
|
|
XLogRegisterBuffer(0, *buffer, REGBUF_STANDARD);
|
|
|
|
xlrec.offnum = ItemPointerGetOffsetNumber(&tuple->t_self);
|
|
xlrec.locking_xid = xid;
|
|
xlrec.infobits_set = compute_infobits(new_infomask,
|
|
tuple->t_data->t_infomask2);
|
|
xlrec.flags = cleared_all_frozen ? XLH_LOCK_ALL_FROZEN_CLEARED : 0;
|
|
XLogRegisterData((char *) &xlrec, SizeOfHeapLock);
|
|
|
|
/* we don't decode row locks atm, so no need to log the origin */
|
|
|
|
recptr = XLogInsert(RM_HEAP_ID, XLOG_HEAP_LOCK);
|
|
|
|
PageSetLSN(page, recptr);
|
|
}
|
|
|
|
END_CRIT_SECTION();
|
|
|
|
result = HeapTupleMayBeUpdated;
|
|
|
|
out_locked:
|
|
LockBuffer(*buffer, BUFFER_LOCK_UNLOCK);
|
|
|
|
out_unlocked:
|
|
if (BufferIsValid(vmbuffer))
|
|
ReleaseBuffer(vmbuffer);
|
|
|
|
/*
|
|
* Don't update the visibility map here. Locking a tuple doesn't change
|
|
* visibility info.
|
|
*/
|
|
|
|
/*
|
|
* Now that we have successfully marked the tuple as locked, we can
|
|
* release the lmgr tuple lock, if we had it.
|
|
*/
|
|
if (have_tuple_lock)
|
|
UnlockTupleTuplock(relation, tid, mode);
|
|
|
|
return result;
|
|
}
|
|
|
|
/*
|
|
* Acquire heavyweight lock on the given tuple, in preparation for acquiring
|
|
* its normal, Xmax-based tuple lock.
|
|
*
|
|
* have_tuple_lock is an input and output parameter: on input, it indicates
|
|
* whether the lock has previously been acquired (and this function does
|
|
* nothing in that case). If this function returns success, have_tuple_lock
|
|
* has been flipped to true.
|
|
*
|
|
* Returns false if it was unable to obtain the lock; this can only happen if
|
|
* wait_policy is Skip.
|
|
*/
|
|
static bool
|
|
heap_acquire_tuplock(Relation relation, ItemPointer tid, LockTupleMode mode,
|
|
LockWaitPolicy wait_policy, bool *have_tuple_lock)
|
|
{
|
|
if (*have_tuple_lock)
|
|
return true;
|
|
|
|
switch (wait_policy)
|
|
{
|
|
case LockWaitBlock:
|
|
LockTupleTuplock(relation, tid, mode);
|
|
break;
|
|
|
|
case LockWaitSkip:
|
|
if (!ConditionalLockTupleTuplock(relation, tid, mode))
|
|
return false;
|
|
break;
|
|
|
|
case LockWaitError:
|
|
if (!ConditionalLockTupleTuplock(relation, tid, mode))
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_LOCK_NOT_AVAILABLE),
|
|
errmsg("could not obtain lock on row in relation \"%s\"",
|
|
RelationGetRelationName(relation))));
|
|
break;
|
|
}
|
|
*have_tuple_lock = true;
|
|
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* Given an original set of Xmax and infomask, and a transaction (identified by
|
|
* add_to_xmax) acquiring a new lock of some mode, compute the new Xmax and
|
|
* corresponding infomasks to use on the tuple.
|
|
*
|
|
* Note that this might have side effects such as creating a new MultiXactId.
|
|
*
|
|
* Most callers will have called HeapTupleSatisfiesUpdate before this function;
|
|
* that will have set the HEAP_XMAX_INVALID bit if the xmax was a MultiXactId
|
|
* but it was not running anymore. There is a race condition, which is that the
|
|
* MultiXactId may have finished since then, but that uncommon case is handled
|
|
* either here, or within MultiXactIdExpand.
|
|
*
|
|
* There is a similar race condition possible when the old xmax was a regular
|
|
* TransactionId. We test TransactionIdIsInProgress again just to narrow the
|
|
* window, but it's still possible to end up creating an unnecessary
|
|
* MultiXactId. Fortunately this is harmless.
|
|
*/
|
|
static void
|
|
compute_new_xmax_infomask(TransactionId xmax, uint16 old_infomask,
|
|
uint16 old_infomask2, TransactionId add_to_xmax,
|
|
LockTupleMode mode, bool is_update,
|
|
TransactionId *result_xmax, uint16 *result_infomask,
|
|
uint16 *result_infomask2)
|
|
{
|
|
TransactionId new_xmax;
|
|
uint16 new_infomask,
|
|
new_infomask2;
|
|
|
|
Assert(TransactionIdIsCurrentTransactionId(add_to_xmax));
|
|
|
|
l5:
|
|
new_infomask = 0;
|
|
new_infomask2 = 0;
|
|
if (old_infomask & HEAP_XMAX_INVALID)
|
|
{
|
|
/*
|
|
* No previous locker; we just insert our own TransactionId.
|
|
*
|
|
* Note that it's critical that this case be the first one checked,
|
|
* because there are several blocks below that come back to this one
|
|
* to implement certain optimizations; old_infomask might contain
|
|
* other dirty bits in those cases, but we don't really care.
|
|
*/
|
|
if (is_update)
|
|
{
|
|
new_xmax = add_to_xmax;
|
|
if (mode == LockTupleExclusive)
|
|
new_infomask2 |= HEAP_KEYS_UPDATED;
|
|
}
|
|
else
|
|
{
|
|
new_infomask |= HEAP_XMAX_LOCK_ONLY;
|
|
switch (mode)
|
|
{
|
|
case LockTupleKeyShare:
|
|
new_xmax = add_to_xmax;
|
|
new_infomask |= HEAP_XMAX_KEYSHR_LOCK;
|
|
break;
|
|
case LockTupleShare:
|
|
new_xmax = add_to_xmax;
|
|
new_infomask |= HEAP_XMAX_SHR_LOCK;
|
|
break;
|
|
case LockTupleNoKeyExclusive:
|
|
new_xmax = add_to_xmax;
|
|
new_infomask |= HEAP_XMAX_EXCL_LOCK;
|
|
break;
|
|
case LockTupleExclusive:
|
|
new_xmax = add_to_xmax;
|
|
new_infomask |= HEAP_XMAX_EXCL_LOCK;
|
|
new_infomask2 |= HEAP_KEYS_UPDATED;
|
|
break;
|
|
default:
|
|
new_xmax = InvalidTransactionId; /* silence compiler */
|
|
elog(ERROR, "invalid lock mode");
|
|
}
|
|
}
|
|
}
|
|
else if (old_infomask & HEAP_XMAX_IS_MULTI)
|
|
{
|
|
MultiXactStatus new_status;
|
|
|
|
/*
|
|
* Currently we don't allow XMAX_COMMITTED to be set for multis, so
|
|
* cross-check.
|
|
*/
|
|
Assert(!(old_infomask & HEAP_XMAX_COMMITTED));
|
|
|
|
/*
|
|
* A multixact together with LOCK_ONLY set but neither lock bit set
|
|
* (i.e. a pg_upgraded share locked tuple) cannot possibly be running
|
|
* anymore. This check is critical for databases upgraded by
|
|
* pg_upgrade; both MultiXactIdIsRunning and MultiXactIdExpand assume
|
|
* that such multis are never passed.
|
|
*/
|
|
if (HEAP_LOCKED_UPGRADED(old_infomask))
|
|
{
|
|
old_infomask &= ~HEAP_XMAX_IS_MULTI;
|
|
old_infomask |= HEAP_XMAX_INVALID;
|
|
goto l5;
|
|
}
|
|
|
|
/*
|
|
* If the XMAX is already a MultiXactId, then we need to expand it to
|
|
* include add_to_xmax; but if all the members were lockers and are
|
|
* all gone, we can do away with the IS_MULTI bit and just set
|
|
* add_to_xmax as the only locker/updater. If all lockers are gone
|
|
* and we have an updater that aborted, we can also do without a
|
|
* multi.
|
|
*
|
|
* The cost of doing GetMultiXactIdMembers would be paid by
|
|
* MultiXactIdExpand if we weren't to do this, so this check is not
|
|
* incurring extra work anyhow.
|
|
*/
|
|
if (!MultiXactIdIsRunning(xmax, HEAP_XMAX_IS_LOCKED_ONLY(old_infomask)))
|
|
{
|
|
if (HEAP_XMAX_IS_LOCKED_ONLY(old_infomask) ||
|
|
!TransactionIdDidCommit(MultiXactIdGetUpdateXid(xmax,
|
|
old_infomask)))
|
|
{
|
|
/*
|
|
* Reset these bits and restart; otherwise fall through to
|
|
* create a new multi below.
|
|
*/
|
|
old_infomask &= ~HEAP_XMAX_IS_MULTI;
|
|
old_infomask |= HEAP_XMAX_INVALID;
|
|
goto l5;
|
|
}
|
|
}
|
|
|
|
new_status = get_mxact_status_for_lock(mode, is_update);
|
|
|
|
new_xmax = MultiXactIdExpand((MultiXactId) xmax, add_to_xmax,
|
|
new_status);
|
|
GetMultiXactIdHintBits(new_xmax, &new_infomask, &new_infomask2);
|
|
}
|
|
else if (old_infomask & HEAP_XMAX_COMMITTED)
|
|
{
|
|
/*
|
|
* It's a committed update, so we need to preserve him as updater of
|
|
* the tuple.
|
|
*/
|
|
MultiXactStatus status;
|
|
MultiXactStatus new_status;
|
|
|
|
if (old_infomask2 & HEAP_KEYS_UPDATED)
|
|
status = MultiXactStatusUpdate;
|
|
else
|
|
status = MultiXactStatusNoKeyUpdate;
|
|
|
|
new_status = get_mxact_status_for_lock(mode, is_update);
|
|
|
|
/*
|
|
* since it's not running, it's obviously impossible for the old
|
|
* updater to be identical to the current one, so we need not check
|
|
* for that case as we do in the block above.
|
|
*/
|
|
new_xmax = MultiXactIdCreate(xmax, status, add_to_xmax, new_status);
|
|
GetMultiXactIdHintBits(new_xmax, &new_infomask, &new_infomask2);
|
|
}
|
|
else if (TransactionIdIsInProgress(xmax))
|
|
{
|
|
/*
|
|
* If the XMAX is a valid, in-progress TransactionId, then we need to
|
|
* create a new MultiXactId that includes both the old locker or
|
|
* updater and our own TransactionId.
|
|
*/
|
|
MultiXactStatus new_status;
|
|
MultiXactStatus old_status;
|
|
LockTupleMode old_mode;
|
|
|
|
if (HEAP_XMAX_IS_LOCKED_ONLY(old_infomask))
|
|
{
|
|
if (HEAP_XMAX_IS_KEYSHR_LOCKED(old_infomask))
|
|
old_status = MultiXactStatusForKeyShare;
|
|
else if (HEAP_XMAX_IS_SHR_LOCKED(old_infomask))
|
|
old_status = MultiXactStatusForShare;
|
|
else if (HEAP_XMAX_IS_EXCL_LOCKED(old_infomask))
|
|
{
|
|
if (old_infomask2 & HEAP_KEYS_UPDATED)
|
|
old_status = MultiXactStatusForUpdate;
|
|
else
|
|
old_status = MultiXactStatusForNoKeyUpdate;
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* LOCK_ONLY can be present alone only when a page has been
|
|
* upgraded by pg_upgrade. But in that case,
|
|
* TransactionIdIsInProgress() should have returned false. We
|
|
* assume it's no longer locked in this case.
|
|
*/
|
|
elog(WARNING, "LOCK_ONLY found for Xid in progress %u", xmax);
|
|
old_infomask |= HEAP_XMAX_INVALID;
|
|
old_infomask &= ~HEAP_XMAX_LOCK_ONLY;
|
|
goto l5;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* it's an update, but which kind? */
|
|
if (old_infomask2 & HEAP_KEYS_UPDATED)
|
|
old_status = MultiXactStatusUpdate;
|
|
else
|
|
old_status = MultiXactStatusNoKeyUpdate;
|
|
}
|
|
|
|
old_mode = TUPLOCK_from_mxstatus(old_status);
|
|
|
|
/*
|
|
* If the lock to be acquired is for the same TransactionId as the
|
|
* existing lock, there's an optimization possible: consider only the
|
|
* strongest of both locks as the only one present, and restart.
|
|
*/
|
|
if (xmax == add_to_xmax)
|
|
{
|
|
/*
|
|
* Note that it's not possible for the original tuple to be
|
|
* updated: we wouldn't be here because the tuple would have been
|
|
* invisible and we wouldn't try to update it. As a subtlety,
|
|
* this code can also run when traversing an update chain to lock
|
|
* future versions of a tuple. But we wouldn't be here either,
|
|
* because the add_to_xmax would be different from the original
|
|
* updater.
|
|
*/
|
|
Assert(HEAP_XMAX_IS_LOCKED_ONLY(old_infomask));
|
|
|
|
/* acquire the strongest of both */
|
|
if (mode < old_mode)
|
|
mode = old_mode;
|
|
/* mustn't touch is_update */
|
|
|
|
old_infomask |= HEAP_XMAX_INVALID;
|
|
goto l5;
|
|
}
|
|
|
|
/* otherwise, just fall back to creating a new multixact */
|
|
new_status = get_mxact_status_for_lock(mode, is_update);
|
|
new_xmax = MultiXactIdCreate(xmax, old_status,
|
|
add_to_xmax, new_status);
|
|
GetMultiXactIdHintBits(new_xmax, &new_infomask, &new_infomask2);
|
|
}
|
|
else if (!HEAP_XMAX_IS_LOCKED_ONLY(old_infomask) &&
|
|
TransactionIdDidCommit(xmax))
|
|
{
|
|
/*
|
|
* It's a committed update, so we gotta preserve him as updater of the
|
|
* tuple.
|
|
*/
|
|
MultiXactStatus status;
|
|
MultiXactStatus new_status;
|
|
|
|
if (old_infomask2 & HEAP_KEYS_UPDATED)
|
|
status = MultiXactStatusUpdate;
|
|
else
|
|
status = MultiXactStatusNoKeyUpdate;
|
|
|
|
new_status = get_mxact_status_for_lock(mode, is_update);
|
|
|
|
/*
|
|
* since it's not running, it's obviously impossible for the old
|
|
* updater to be identical to the current one, so we need not check
|
|
* for that case as we do in the block above.
|
|
*/
|
|
new_xmax = MultiXactIdCreate(xmax, status, add_to_xmax, new_status);
|
|
GetMultiXactIdHintBits(new_xmax, &new_infomask, &new_infomask2);
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* Can get here iff the locking/updating transaction was running when
|
|
* the infomask was extracted from the tuple, but finished before
|
|
* TransactionIdIsInProgress got to run. Deal with it as if there was
|
|
* no locker at all in the first place.
|
|
*/
|
|
old_infomask |= HEAP_XMAX_INVALID;
|
|
goto l5;
|
|
}
|
|
|
|
*result_infomask = new_infomask;
|
|
*result_infomask2 = new_infomask2;
|
|
*result_xmax = new_xmax;
|
|
}
|
|
|
|
/*
|
|
* Subroutine for heap_lock_updated_tuple_rec.
|
|
*
|
|
* Given a hypothetical multixact status held by the transaction identified
|
|
* with the given xid, does the current transaction need to wait, fail, or can
|
|
* it continue if it wanted to acquire a lock of the given mode? "needwait"
|
|
* is set to true if waiting is necessary; if it can continue, then
|
|
* HeapTupleMayBeUpdated is returned. If the lock is already held by the
|
|
* current transaction, return HeapTupleSelfUpdated. In case of a conflict
|
|
* with another transaction, a different HeapTupleSatisfiesUpdate return code
|
|
* is returned.
|
|
*
|
|
* The held status is said to be hypothetical because it might correspond to a
|
|
* lock held by a single Xid, i.e. not a real MultiXactId; we express it this
|
|
* way for simplicity of API.
|
|
*/
|
|
static HTSU_Result
|
|
test_lockmode_for_conflict(MultiXactStatus status, TransactionId xid,
|
|
LockTupleMode mode, bool *needwait)
|
|
{
|
|
MultiXactStatus wantedstatus;
|
|
|
|
*needwait = false;
|
|
wantedstatus = get_mxact_status_for_lock(mode, false);
|
|
|
|
/*
|
|
* Note: we *must* check TransactionIdIsInProgress before
|
|
* TransactionIdDidAbort/Commit; see comment at top of tqual.c for an
|
|
* explanation.
|
|
*/
|
|
if (TransactionIdIsCurrentTransactionId(xid))
|
|
{
|
|
/*
|
|
* The tuple has already been locked by our own transaction. This is
|
|
* very rare but can happen if multiple transactions are trying to
|
|
* lock an ancient version of the same tuple.
|
|
*/
|
|
return HeapTupleSelfUpdated;
|
|
}
|
|
else if (TransactionIdIsInProgress(xid))
|
|
{
|
|
/*
|
|
* If the locking transaction is running, what we do depends on
|
|
* whether the lock modes conflict: if they do, then we must wait for
|
|
* it to finish; otherwise we can fall through to lock this tuple
|
|
* version without waiting.
|
|
*/
|
|
if (DoLockModesConflict(LOCKMODE_from_mxstatus(status),
|
|
LOCKMODE_from_mxstatus(wantedstatus)))
|
|
{
|
|
*needwait = true;
|
|
}
|
|
|
|
/*
|
|
* If we set needwait above, then this value doesn't matter;
|
|
* otherwise, this value signals to caller that it's okay to proceed.
|
|
*/
|
|
return HeapTupleMayBeUpdated;
|
|
}
|
|
else if (TransactionIdDidAbort(xid))
|
|
return HeapTupleMayBeUpdated;
|
|
else if (TransactionIdDidCommit(xid))
|
|
{
|
|
/*
|
|
* The other transaction committed. If it was only a locker, then the
|
|
* lock is completely gone now and we can return success; but if it
|
|
* was an update, then what we do depends on whether the two lock
|
|
* modes conflict. If they conflict, then we must report error to
|
|
* caller. But if they don't, we can fall through to allow the current
|
|
* transaction to lock the tuple.
|
|
*
|
|
* Note: the reason we worry about ISUPDATE here is because as soon as
|
|
* a transaction ends, all its locks are gone and meaningless, and
|
|
* thus we can ignore them; whereas its updates persist. In the
|
|
* TransactionIdIsInProgress case, above, we don't need to check
|
|
* because we know the lock is still "alive" and thus a conflict needs
|
|
* always be checked.
|
|
*/
|
|
if (!ISUPDATE_from_mxstatus(status))
|
|
return HeapTupleMayBeUpdated;
|
|
|
|
if (DoLockModesConflict(LOCKMODE_from_mxstatus(status),
|
|
LOCKMODE_from_mxstatus(wantedstatus)))
|
|
/* bummer */
|
|
return HeapTupleUpdated;
|
|
|
|
return HeapTupleMayBeUpdated;
|
|
}
|
|
|
|
/* Not in progress, not aborted, not committed -- must have crashed */
|
|
return HeapTupleMayBeUpdated;
|
|
}
|
|
|
|
|
|
/*
|
|
* Recursive part of heap_lock_updated_tuple
|
|
*
|
|
* Fetch the tuple pointed to by tid in rel, and mark it as locked by the given
|
|
* xid with the given mode; if this tuple is updated, recurse to lock the new
|
|
* version as well.
|
|
*/
|
|
static HTSU_Result
|
|
heap_lock_updated_tuple_rec(Relation rel, ItemPointer tid, TransactionId xid,
|
|
LockTupleMode mode)
|
|
{
|
|
HTSU_Result result;
|
|
ItemPointerData tupid;
|
|
HeapTupleData mytup;
|
|
Buffer buf;
|
|
uint16 new_infomask,
|
|
new_infomask2,
|
|
old_infomask,
|
|
old_infomask2;
|
|
TransactionId xmax,
|
|
new_xmax;
|
|
TransactionId priorXmax = InvalidTransactionId;
|
|
bool cleared_all_frozen = false;
|
|
Buffer vmbuffer = InvalidBuffer;
|
|
BlockNumber block;
|
|
|
|
ItemPointerCopy(tid, &tupid);
|
|
|
|
for (;;)
|
|
{
|
|
new_infomask = 0;
|
|
new_xmax = InvalidTransactionId;
|
|
block = ItemPointerGetBlockNumber(&tupid);
|
|
ItemPointerCopy(&tupid, &(mytup.t_self));
|
|
|
|
if (!heap_fetch(rel, SnapshotAny, &mytup, &buf, false, NULL))
|
|
{
|
|
/*
|
|
* if we fail to find the updated version of the tuple, it's
|
|
* because it was vacuumed/pruned away after its creator
|
|
* transaction aborted. So behave as if we got to the end of the
|
|
* chain, and there's no further tuple to lock: return success to
|
|
* caller.
|
|
*/
|
|
return HeapTupleMayBeUpdated;
|
|
}
|
|
|
|
l4:
|
|
CHECK_FOR_INTERRUPTS();
|
|
|
|
/*
|
|
* Before locking the buffer, pin the visibility map page if it
|
|
* appears to be necessary. Since we haven't got the lock yet,
|
|
* someone else might be in the middle of changing this, so we'll need
|
|
* to recheck after we have the lock.
|
|
*/
|
|
if (PageIsAllVisible(BufferGetPage(buf)))
|
|
visibilitymap_pin(rel, block, &vmbuffer);
|
|
else
|
|
vmbuffer = InvalidBuffer;
|
|
|
|
LockBuffer(buf, BUFFER_LOCK_EXCLUSIVE);
|
|
|
|
/*
|
|
* If we didn't pin the visibility map page and the page has become
|
|
* all visible while we were busy locking the buffer, we'll have to
|
|
* unlock and re-lock, to avoid holding the buffer lock across I/O.
|
|
* That's a bit unfortunate, but hopefully shouldn't happen often.
|
|
*/
|
|
if (vmbuffer == InvalidBuffer && PageIsAllVisible(BufferGetPage(buf)))
|
|
{
|
|
LockBuffer(buf, BUFFER_LOCK_UNLOCK);
|
|
visibilitymap_pin(rel, block, &vmbuffer);
|
|
LockBuffer(buf, BUFFER_LOCK_EXCLUSIVE);
|
|
}
|
|
|
|
/*
|
|
* Check the tuple XMIN against prior XMAX, if any. If we reached the
|
|
* end of the chain, we're done, so return success.
|
|
*/
|
|
if (TransactionIdIsValid(priorXmax) &&
|
|
!TransactionIdEquals(HeapTupleHeaderGetXmin(mytup.t_data),
|
|
priorXmax))
|
|
{
|
|
result = HeapTupleMayBeUpdated;
|
|
goto out_locked;
|
|
}
|
|
|
|
/*
|
|
* Also check Xmin: if this tuple was created by an aborted
|
|
* (sub)transaction, then we already locked the last live one in the
|
|
* chain, thus we're done, so return success.
|
|
*/
|
|
if (TransactionIdDidAbort(HeapTupleHeaderGetXmin(mytup.t_data)))
|
|
{
|
|
UnlockReleaseBuffer(buf);
|
|
return HeapTupleMayBeUpdated;
|
|
}
|
|
|
|
old_infomask = mytup.t_data->t_infomask;
|
|
old_infomask2 = mytup.t_data->t_infomask2;
|
|
xmax = HeapTupleHeaderGetRawXmax(mytup.t_data);
|
|
|
|
/*
|
|
* If this tuple version has been updated or locked by some concurrent
|
|
* transaction(s), what we do depends on whether our lock mode
|
|
* conflicts with what those other transactions hold, and also on the
|
|
* status of them.
|
|
*/
|
|
if (!(old_infomask & HEAP_XMAX_INVALID))
|
|
{
|
|
TransactionId rawxmax;
|
|
bool needwait;
|
|
|
|
rawxmax = HeapTupleHeaderGetRawXmax(mytup.t_data);
|
|
if (old_infomask & HEAP_XMAX_IS_MULTI)
|
|
{
|
|
int nmembers;
|
|
int i;
|
|
MultiXactMember *members;
|
|
|
|
/*
|
|
* We don't need a test for pg_upgrade'd tuples: this is only
|
|
* applied to tuples after the first in an update chain. Said
|
|
* first tuple in the chain may well be locked-in-9.2-and-
|
|
* pg_upgraded, but that one was already locked by our caller,
|
|
* not us; and any subsequent ones cannot be because our
|
|
* caller must necessarily have obtained a snapshot later than
|
|
* the pg_upgrade itself.
|
|
*/
|
|
Assert(!HEAP_LOCKED_UPGRADED(mytup.t_data->t_infomask));
|
|
|
|
nmembers = GetMultiXactIdMembers(rawxmax, &members, false,
|
|
HEAP_XMAX_IS_LOCKED_ONLY(old_infomask));
|
|
for (i = 0; i < nmembers; i++)
|
|
{
|
|
result = test_lockmode_for_conflict(members[i].status,
|
|
members[i].xid,
|
|
mode, &needwait);
|
|
|
|
/*
|
|
* If the tuple was already locked by ourselves in a
|
|
* previous iteration of this (say heap_lock_tuple was
|
|
* forced to restart the locking loop because of a change
|
|
* in xmax), then we hold the lock already on this tuple
|
|
* version and we don't need to do anything; and this is
|
|
* not an error condition either. We just need to skip
|
|
* this tuple and continue locking the next version in the
|
|
* update chain.
|
|
*/
|
|
if (result == HeapTupleSelfUpdated)
|
|
{
|
|
pfree(members);
|
|
goto next;
|
|
}
|
|
|
|
if (needwait)
|
|
{
|
|
LockBuffer(buf, BUFFER_LOCK_UNLOCK);
|
|
XactLockTableWait(members[i].xid, rel,
|
|
&mytup.t_self,
|
|
XLTW_LockUpdated);
|
|
pfree(members);
|
|
goto l4;
|
|
}
|
|
if (result != HeapTupleMayBeUpdated)
|
|
{
|
|
pfree(members);
|
|
goto out_locked;
|
|
}
|
|
}
|
|
if (members)
|
|
pfree(members);
|
|
}
|
|
else
|
|
{
|
|
MultiXactStatus status;
|
|
|
|
/*
|
|
* For a non-multi Xmax, we first need to compute the
|
|
* corresponding MultiXactStatus by using the infomask bits.
|
|
*/
|
|
if (HEAP_XMAX_IS_LOCKED_ONLY(old_infomask))
|
|
{
|
|
if (HEAP_XMAX_IS_KEYSHR_LOCKED(old_infomask))
|
|
status = MultiXactStatusForKeyShare;
|
|
else if (HEAP_XMAX_IS_SHR_LOCKED(old_infomask))
|
|
status = MultiXactStatusForShare;
|
|
else if (HEAP_XMAX_IS_EXCL_LOCKED(old_infomask))
|
|
{
|
|
if (old_infomask2 & HEAP_KEYS_UPDATED)
|
|
status = MultiXactStatusForUpdate;
|
|
else
|
|
status = MultiXactStatusForNoKeyUpdate;
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* LOCK_ONLY present alone (a pg_upgraded tuple marked
|
|
* as share-locked in the old cluster) shouldn't be
|
|
* seen in the middle of an update chain.
|
|
*/
|
|
elog(ERROR, "invalid lock status in tuple");
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* it's an update, but which kind? */
|
|
if (old_infomask2 & HEAP_KEYS_UPDATED)
|
|
status = MultiXactStatusUpdate;
|
|
else
|
|
status = MultiXactStatusNoKeyUpdate;
|
|
}
|
|
|
|
result = test_lockmode_for_conflict(status, rawxmax, mode,
|
|
&needwait);
|
|
|
|
/*
|
|
* If the tuple was already locked by ourselves in a previous
|
|
* iteration of this (say heap_lock_tuple was forced to
|
|
* restart the locking loop because of a change in xmax), then
|
|
* we hold the lock already on this tuple version and we don't
|
|
* need to do anything; and this is not an error condition
|
|
* either. We just need to skip this tuple and continue
|
|
* locking the next version in the update chain.
|
|
*/
|
|
if (result == HeapTupleSelfUpdated)
|
|
goto next;
|
|
|
|
if (needwait)
|
|
{
|
|
LockBuffer(buf, BUFFER_LOCK_UNLOCK);
|
|
XactLockTableWait(rawxmax, rel, &mytup.t_self,
|
|
XLTW_LockUpdated);
|
|
goto l4;
|
|
}
|
|
if (result != HeapTupleMayBeUpdated)
|
|
{
|
|
goto out_locked;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* compute the new Xmax and infomask values for the tuple ... */
|
|
compute_new_xmax_infomask(xmax, old_infomask, mytup.t_data->t_infomask2,
|
|
xid, mode, false,
|
|
&new_xmax, &new_infomask, &new_infomask2);
|
|
|
|
if (PageIsAllVisible(BufferGetPage(buf)) &&
|
|
visibilitymap_clear(rel, block, vmbuffer,
|
|
VISIBILITYMAP_ALL_FROZEN))
|
|
cleared_all_frozen = true;
|
|
|
|
START_CRIT_SECTION();
|
|
|
|
/* ... and set them */
|
|
HeapTupleHeaderSetXmax(mytup.t_data, new_xmax);
|
|
mytup.t_data->t_infomask &= ~HEAP_XMAX_BITS;
|
|
mytup.t_data->t_infomask2 &= ~HEAP_KEYS_UPDATED;
|
|
mytup.t_data->t_infomask |= new_infomask;
|
|
mytup.t_data->t_infomask2 |= new_infomask2;
|
|
|
|
MarkBufferDirty(buf);
|
|
|
|
/* XLOG stuff */
|
|
if (RelationNeedsWAL(rel))
|
|
{
|
|
xl_heap_lock_updated xlrec;
|
|
XLogRecPtr recptr;
|
|
Page page = BufferGetPage(buf);
|
|
|
|
XLogBeginInsert();
|
|
XLogRegisterBuffer(0, buf, REGBUF_STANDARD);
|
|
|
|
xlrec.offnum = ItemPointerGetOffsetNumber(&mytup.t_self);
|
|
xlrec.xmax = new_xmax;
|
|
xlrec.infobits_set = compute_infobits(new_infomask, new_infomask2);
|
|
xlrec.flags =
|
|
cleared_all_frozen ? XLH_LOCK_ALL_FROZEN_CLEARED : 0;
|
|
|
|
XLogRegisterData((char *) &xlrec, SizeOfHeapLockUpdated);
|
|
|
|
recptr = XLogInsert(RM_HEAP2_ID, XLOG_HEAP2_LOCK_UPDATED);
|
|
|
|
PageSetLSN(page, recptr);
|
|
}
|
|
|
|
END_CRIT_SECTION();
|
|
|
|
next:
|
|
/* if we find the end of update chain, we're done. */
|
|
if (mytup.t_data->t_infomask & HEAP_XMAX_INVALID ||
|
|
ItemPointerEquals(&mytup.t_self, &mytup.t_data->t_ctid) ||
|
|
HeapTupleHeaderIsOnlyLocked(mytup.t_data))
|
|
{
|
|
result = HeapTupleMayBeUpdated;
|
|
goto out_locked;
|
|
}
|
|
|
|
/* tail recursion */
|
|
priorXmax = HeapTupleHeaderGetUpdateXid(mytup.t_data);
|
|
ItemPointerCopy(&(mytup.t_data->t_ctid), &tupid);
|
|
UnlockReleaseBuffer(buf);
|
|
if (vmbuffer != InvalidBuffer)
|
|
ReleaseBuffer(vmbuffer);
|
|
}
|
|
|
|
result = HeapTupleMayBeUpdated;
|
|
|
|
out_locked:
|
|
UnlockReleaseBuffer(buf);
|
|
|
|
if (vmbuffer != InvalidBuffer)
|
|
ReleaseBuffer(vmbuffer);
|
|
|
|
return result;
|
|
|
|
}
|
|
|
|
/*
|
|
* heap_lock_updated_tuple
|
|
* Follow update chain when locking an updated tuple, acquiring locks (row
|
|
* marks) on the updated versions.
|
|
*
|
|
* The initial tuple is assumed to be already locked.
|
|
*
|
|
* This function doesn't check visibility, it just unconditionally marks the
|
|
* tuple(s) as locked. If any tuple in the updated chain is being deleted
|
|
* concurrently (or updated with the key being modified), sleep until the
|
|
* transaction doing it is finished.
|
|
*
|
|
* Note that we don't acquire heavyweight tuple locks on the tuples we walk
|
|
* when we have to wait for other transactions to release them, as opposed to
|
|
* what heap_lock_tuple does. The reason is that having more than one
|
|
* transaction walking the chain is probably uncommon enough that risk of
|
|
* starvation is not likely: one of the preconditions for being here is that
|
|
* the snapshot in use predates the update that created this tuple (because we
|
|
* started at an earlier version of the tuple), but at the same time such a
|
|
* transaction cannot be using repeatable read or serializable isolation
|
|
* levels, because that would lead to a serializability failure.
|
|
*/
|
|
static HTSU_Result
|
|
heap_lock_updated_tuple(Relation rel, HeapTuple tuple, ItemPointer ctid,
|
|
TransactionId xid, LockTupleMode mode)
|
|
{
|
|
if (!ItemPointerEquals(&tuple->t_self, ctid))
|
|
{
|
|
/*
|
|
* If this is the first possibly-multixact-able operation in the
|
|
* current transaction, set my per-backend OldestMemberMXactId
|
|
* setting. We can be certain that the transaction will never become a
|
|
* member of any older MultiXactIds than that. (We have to do this
|
|
* even if we end up just using our own TransactionId below, since
|
|
* some other backend could incorporate our XID into a MultiXact
|
|
* immediately afterwards.)
|
|
*/
|
|
MultiXactIdSetOldestMember();
|
|
|
|
return heap_lock_updated_tuple_rec(rel, ctid, xid, mode);
|
|
}
|
|
|
|
/* nothing to lock */
|
|
return HeapTupleMayBeUpdated;
|
|
}
|
|
|
|
/*
|
|
* heap_finish_speculative - mark speculative insertion as successful
|
|
*
|
|
* To successfully finish a speculative insertion we have to clear speculative
|
|
* token from tuple. To do so the t_ctid field, which will contain a
|
|
* speculative token value, is modified in place to point to the tuple itself,
|
|
* which is characteristic of a newly inserted ordinary tuple.
|
|
*
|
|
* NB: It is not ok to commit without either finishing or aborting a
|
|
* speculative insertion. We could treat speculative tuples of committed
|
|
* transactions implicitly as completed, but then we would have to be prepared
|
|
* to deal with speculative tokens on committed tuples. That wouldn't be
|
|
* difficult - no-one looks at the ctid field of a tuple with invalid xmax -
|
|
* but clearing the token at completion isn't very expensive either.
|
|
* An explicit confirmation WAL record also makes logical decoding simpler.
|
|
*/
|
|
void
|
|
heap_finish_speculative(Relation relation, HeapTuple tuple)
|
|
{
|
|
Buffer buffer;
|
|
Page page;
|
|
OffsetNumber offnum;
|
|
ItemId lp = NULL;
|
|
HeapTupleHeader htup;
|
|
|
|
buffer = ReadBuffer(relation, ItemPointerGetBlockNumber(&(tuple->t_self)));
|
|
LockBuffer(buffer, BUFFER_LOCK_EXCLUSIVE);
|
|
page = (Page) BufferGetPage(buffer);
|
|
|
|
offnum = ItemPointerGetOffsetNumber(&(tuple->t_self));
|
|
if (PageGetMaxOffsetNumber(page) >= offnum)
|
|
lp = PageGetItemId(page, offnum);
|
|
|
|
if (PageGetMaxOffsetNumber(page) < offnum || !ItemIdIsNormal(lp))
|
|
elog(ERROR, "invalid lp");
|
|
|
|
htup = (HeapTupleHeader) PageGetItem(page, lp);
|
|
|
|
/* SpecTokenOffsetNumber should be distinguishable from any real offset */
|
|
StaticAssertStmt(MaxOffsetNumber < SpecTokenOffsetNumber,
|
|
"invalid speculative token constant");
|
|
|
|
/* NO EREPORT(ERROR) from here till changes are logged */
|
|
START_CRIT_SECTION();
|
|
|
|
Assert(HeapTupleHeaderIsSpeculative(tuple->t_data));
|
|
|
|
MarkBufferDirty(buffer);
|
|
|
|
/*
|
|
* Replace the speculative insertion token with a real t_ctid, pointing to
|
|
* itself like it does on regular tuples.
|
|
*/
|
|
htup->t_ctid = tuple->t_self;
|
|
|
|
/* XLOG stuff */
|
|
if (RelationNeedsWAL(relation))
|
|
{
|
|
xl_heap_confirm xlrec;
|
|
XLogRecPtr recptr;
|
|
|
|
xlrec.offnum = ItemPointerGetOffsetNumber(&tuple->t_self);
|
|
|
|
XLogBeginInsert();
|
|
|
|
/* We want the same filtering on this as on a plain insert */
|
|
XLogSetRecordFlags(XLOG_INCLUDE_ORIGIN);
|
|
|
|
XLogRegisterData((char *) &xlrec, SizeOfHeapConfirm);
|
|
XLogRegisterBuffer(0, buffer, REGBUF_STANDARD);
|
|
|
|
recptr = XLogInsert(RM_HEAP_ID, XLOG_HEAP_CONFIRM);
|
|
|
|
PageSetLSN(page, recptr);
|
|
}
|
|
|
|
END_CRIT_SECTION();
|
|
|
|
UnlockReleaseBuffer(buffer);
|
|
}
|
|
|
|
/*
|
|
* heap_abort_speculative - kill a speculatively inserted tuple
|
|
*
|
|
* Marks a tuple that was speculatively inserted in the same command as dead,
|
|
* by setting its xmin as invalid. That makes it immediately appear as dead
|
|
* to all transactions, including our own. In particular, it makes
|
|
* HeapTupleSatisfiesDirty() regard the tuple as dead, so that another backend
|
|
* inserting a duplicate key value won't unnecessarily wait for our whole
|
|
* transaction to finish (it'll just wait for our speculative insertion to
|
|
* finish).
|
|
*
|
|
* Killing the tuple prevents "unprincipled deadlocks", which are deadlocks
|
|
* that arise due to a mutual dependency that is not user visible. By
|
|
* definition, unprincipled deadlocks cannot be prevented by the user
|
|
* reordering lock acquisition in client code, because the implementation level
|
|
* lock acquisitions are not under the user's direct control. If speculative
|
|
* inserters did not take this precaution, then under high concurrency they
|
|
* could deadlock with each other, which would not be acceptable.
|
|
*
|
|
* This is somewhat redundant with heap_delete, but we prefer to have a
|
|
* dedicated routine with stripped down requirements. Note that this is also
|
|
* used to delete the TOAST tuples created during speculative insertion.
|
|
*
|
|
* This routine does not affect logical decoding as it only looks at
|
|
* confirmation records.
|
|
*/
|
|
void
|
|
heap_abort_speculative(Relation relation, HeapTuple tuple)
|
|
{
|
|
TransactionId xid = GetCurrentTransactionId();
|
|
ItemPointer tid = &(tuple->t_self);
|
|
ItemId lp;
|
|
HeapTupleData tp;
|
|
Page page;
|
|
BlockNumber block;
|
|
Buffer buffer;
|
|
|
|
Assert(ItemPointerIsValid(tid));
|
|
|
|
block = ItemPointerGetBlockNumber(tid);
|
|
buffer = ReadBuffer(relation, block);
|
|
page = BufferGetPage(buffer);
|
|
|
|
LockBuffer(buffer, BUFFER_LOCK_EXCLUSIVE);
|
|
|
|
/*
|
|
* Page can't be all visible, we just inserted into it, and are still
|
|
* running.
|
|
*/
|
|
Assert(!PageIsAllVisible(page));
|
|
|
|
lp = PageGetItemId(page, ItemPointerGetOffsetNumber(tid));
|
|
Assert(ItemIdIsNormal(lp));
|
|
|
|
tp.t_tableOid = RelationGetRelid(relation);
|
|
tp.t_data = (HeapTupleHeader) PageGetItem(page, lp);
|
|
tp.t_len = ItemIdGetLength(lp);
|
|
tp.t_self = *tid;
|
|
|
|
/*
|
|
* Sanity check that the tuple really is a speculatively inserted tuple,
|
|
* inserted by us.
|
|
*/
|
|
if (tp.t_data->t_choice.t_heap.t_xmin != xid)
|
|
elog(ERROR, "attempted to kill a tuple inserted by another transaction");
|
|
if (!(IsToastRelation(relation) || HeapTupleHeaderIsSpeculative(tp.t_data)))
|
|
elog(ERROR, "attempted to kill a non-speculative tuple");
|
|
Assert(!HeapTupleHeaderIsHeapOnly(tp.t_data));
|
|
|
|
/*
|
|
* No need to check for serializable conflicts here. There is never a
|
|
* need for a combocid, either. No need to extract replica identity, or
|
|
* do anything special with infomask bits.
|
|
*/
|
|
|
|
START_CRIT_SECTION();
|
|
|
|
/*
|
|
* The tuple will become DEAD immediately. Flag that this page
|
|
* immediately is a candidate for pruning by setting xmin to
|
|
* RecentGlobalXmin. That's not pretty, but it doesn't seem worth
|
|
* inventing a nicer API for this.
|
|
*/
|
|
Assert(TransactionIdIsValid(RecentGlobalXmin));
|
|
PageSetPrunable(page, RecentGlobalXmin);
|
|
|
|
/* store transaction information of xact deleting the tuple */
|
|
tp.t_data->t_infomask &= ~(HEAP_XMAX_BITS | HEAP_MOVED);
|
|
tp.t_data->t_infomask2 &= ~HEAP_KEYS_UPDATED;
|
|
|
|
/*
|
|
* Set the tuple header xmin to InvalidTransactionId. This makes the
|
|
* tuple immediately invisible everyone. (In particular, to any
|
|
* transactions waiting on the speculative token, woken up later.)
|
|
*/
|
|
HeapTupleHeaderSetXmin(tp.t_data, InvalidTransactionId);
|
|
|
|
/* Clear the speculative insertion token too */
|
|
tp.t_data->t_ctid = tp.t_self;
|
|
|
|
MarkBufferDirty(buffer);
|
|
|
|
/*
|
|
* XLOG stuff
|
|
*
|
|
* The WAL records generated here match heap_delete(). The same recovery
|
|
* routines are used.
|
|
*/
|
|
if (RelationNeedsWAL(relation))
|
|
{
|
|
xl_heap_delete xlrec;
|
|
XLogRecPtr recptr;
|
|
|
|
xlrec.flags = XLH_DELETE_IS_SUPER;
|
|
xlrec.infobits_set = compute_infobits(tp.t_data->t_infomask,
|
|
tp.t_data->t_infomask2);
|
|
xlrec.offnum = ItemPointerGetOffsetNumber(&tp.t_self);
|
|
xlrec.xmax = xid;
|
|
|
|
XLogBeginInsert();
|
|
XLogRegisterData((char *) &xlrec, SizeOfHeapDelete);
|
|
XLogRegisterBuffer(0, buffer, REGBUF_STANDARD);
|
|
|
|
/* No replica identity & replication origin logged */
|
|
|
|
recptr = XLogInsert(RM_HEAP_ID, XLOG_HEAP_DELETE);
|
|
|
|
PageSetLSN(page, recptr);
|
|
}
|
|
|
|
END_CRIT_SECTION();
|
|
|
|
LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
|
|
|
|
if (HeapTupleHasExternal(&tp))
|
|
{
|
|
Assert(!IsToastRelation(relation));
|
|
toast_delete(relation, &tp, true);
|
|
}
|
|
|
|
/*
|
|
* Never need to mark tuple for invalidation, since catalogs don't support
|
|
* speculative insertion
|
|
*/
|
|
|
|
/* Now we can release the buffer */
|
|
ReleaseBuffer(buffer);
|
|
|
|
/* count deletion, as we counted the insertion too */
|
|
pgstat_count_heap_delete(relation);
|
|
}
|
|
|
|
/*
|
|
* heap_inplace_update - update a tuple "in place" (ie, overwrite it)
|
|
*
|
|
* Overwriting violates both MVCC and transactional safety, so the uses
|
|
* of this function in Postgres are extremely limited. Nonetheless we
|
|
* find some places to use it.
|
|
*
|
|
* The tuple cannot change size, and therefore it's reasonable to assume
|
|
* that its null bitmap (if any) doesn't change either. So we just
|
|
* overwrite the data portion of the tuple without touching the null
|
|
* bitmap or any of the header fields.
|
|
*
|
|
* tuple is an in-memory tuple structure containing the data to be written
|
|
* over the target tuple. Also, tuple->t_self identifies the target tuple.
|
|
*/
|
|
void
|
|
heap_inplace_update(Relation relation, HeapTuple tuple)
|
|
{
|
|
Buffer buffer;
|
|
Page page;
|
|
OffsetNumber offnum;
|
|
ItemId lp = NULL;
|
|
HeapTupleHeader htup;
|
|
uint32 oldlen;
|
|
uint32 newlen;
|
|
|
|
/*
|
|
* For now, parallel operations are required to be strictly read-only.
|
|
* Unlike a regular update, this should never create a combo CID, so it
|
|
* might be possible to relax this restriction, but not without more
|
|
* thought and testing. It's not clear that it would be useful, anyway.
|
|
*/
|
|
if (IsInParallelMode())
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_INVALID_TRANSACTION_STATE),
|
|
errmsg("cannot update tuples during a parallel operation")));
|
|
|
|
buffer = ReadBuffer(relation, ItemPointerGetBlockNumber(&(tuple->t_self)));
|
|
LockBuffer(buffer, BUFFER_LOCK_EXCLUSIVE);
|
|
page = (Page) BufferGetPage(buffer);
|
|
|
|
offnum = ItemPointerGetOffsetNumber(&(tuple->t_self));
|
|
if (PageGetMaxOffsetNumber(page) >= offnum)
|
|
lp = PageGetItemId(page, offnum);
|
|
|
|
if (PageGetMaxOffsetNumber(page) < offnum || !ItemIdIsNormal(lp))
|
|
elog(ERROR, "invalid lp");
|
|
|
|
htup = (HeapTupleHeader) PageGetItem(page, lp);
|
|
|
|
oldlen = ItemIdGetLength(lp) - htup->t_hoff;
|
|
newlen = tuple->t_len - tuple->t_data->t_hoff;
|
|
if (oldlen != newlen || htup->t_hoff != tuple->t_data->t_hoff)
|
|
elog(ERROR, "wrong tuple length");
|
|
|
|
/* NO EREPORT(ERROR) from here till changes are logged */
|
|
START_CRIT_SECTION();
|
|
|
|
memcpy((char *) htup + htup->t_hoff,
|
|
(char *) tuple->t_data + tuple->t_data->t_hoff,
|
|
newlen);
|
|
|
|
MarkBufferDirty(buffer);
|
|
|
|
/* XLOG stuff */
|
|
if (RelationNeedsWAL(relation))
|
|
{
|
|
xl_heap_inplace xlrec;
|
|
XLogRecPtr recptr;
|
|
|
|
xlrec.offnum = ItemPointerGetOffsetNumber(&tuple->t_self);
|
|
|
|
XLogBeginInsert();
|
|
XLogRegisterData((char *) &xlrec, SizeOfHeapInplace);
|
|
|
|
XLogRegisterBuffer(0, buffer, REGBUF_STANDARD);
|
|
XLogRegisterBufData(0, (char *) htup + htup->t_hoff, newlen);
|
|
|
|
/* inplace updates aren't decoded atm, don't log the origin */
|
|
|
|
recptr = XLogInsert(RM_HEAP_ID, XLOG_HEAP_INPLACE);
|
|
|
|
PageSetLSN(page, recptr);
|
|
}
|
|
|
|
END_CRIT_SECTION();
|
|
|
|
UnlockReleaseBuffer(buffer);
|
|
|
|
/*
|
|
* Send out shared cache inval if necessary. Note that because we only
|
|
* pass the new version of the tuple, this mustn't be used for any
|
|
* operations that could change catcache lookup keys. But we aren't
|
|
* bothering with index updates either, so that's true a fortiori.
|
|
*/
|
|
if (!IsBootstrapProcessingMode())
|
|
CacheInvalidateHeapTuple(relation, tuple, NULL);
|
|
}
|
|
|
|
#define FRM_NOOP 0x0001
|
|
#define FRM_INVALIDATE_XMAX 0x0002
|
|
#define FRM_RETURN_IS_XID 0x0004
|
|
#define FRM_RETURN_IS_MULTI 0x0008
|
|
#define FRM_MARK_COMMITTED 0x0010
|
|
|
|
/*
|
|
* FreezeMultiXactId
|
|
* Determine what to do during freezing when a tuple is marked by a
|
|
* MultiXactId.
|
|
*
|
|
* NB -- this might have the side-effect of creating a new MultiXactId!
|
|
*
|
|
* "flags" is an output value; it's used to tell caller what to do on return.
|
|
* Possible flags are:
|
|
* FRM_NOOP
|
|
* don't do anything -- keep existing Xmax
|
|
* FRM_INVALIDATE_XMAX
|
|
* mark Xmax as InvalidTransactionId and set XMAX_INVALID flag.
|
|
* FRM_RETURN_IS_XID
|
|
* The Xid return value is a single update Xid to set as xmax.
|
|
* FRM_MARK_COMMITTED
|
|
* Xmax can be marked as HEAP_XMAX_COMMITTED
|
|
* FRM_RETURN_IS_MULTI
|
|
* The return value is a new MultiXactId to set as new Xmax.
|
|
* (caller must obtain proper infomask bits using GetMultiXactIdHintBits)
|
|
*/
|
|
static TransactionId
|
|
FreezeMultiXactId(MultiXactId multi, uint16 t_infomask,
|
|
TransactionId relfrozenxid, TransactionId relminmxid,
|
|
TransactionId cutoff_xid, MultiXactId cutoff_multi,
|
|
uint16 *flags)
|
|
{
|
|
TransactionId xid = InvalidTransactionId;
|
|
int i;
|
|
MultiXactMember *members;
|
|
int nmembers;
|
|
bool need_replace;
|
|
int nnewmembers;
|
|
MultiXactMember *newmembers;
|
|
bool has_lockers;
|
|
TransactionId update_xid;
|
|
bool update_committed;
|
|
|
|
*flags = 0;
|
|
|
|
/* We should only be called in Multis */
|
|
Assert(t_infomask & HEAP_XMAX_IS_MULTI);
|
|
|
|
if (!MultiXactIdIsValid(multi) ||
|
|
HEAP_LOCKED_UPGRADED(t_infomask))
|
|
{
|
|
/* Ensure infomask bits are appropriately set/reset */
|
|
*flags |= FRM_INVALIDATE_XMAX;
|
|
return InvalidTransactionId;
|
|
}
|
|
else if (MultiXactIdPrecedes(multi, relminmxid))
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_DATA_CORRUPTED),
|
|
errmsg_internal("found multixact %u from before relminmxid %u",
|
|
multi, relminmxid)));
|
|
else if (MultiXactIdPrecedes(multi, cutoff_multi))
|
|
{
|
|
/*
|
|
* This old multi cannot possibly have members still running, but
|
|
* verify just in case. If it was a locker only, it can be removed
|
|
* without any further consideration; but if it contained an update, we
|
|
* might need to preserve it.
|
|
*/
|
|
if (MultiXactIdIsRunning(multi,
|
|
HEAP_XMAX_IS_LOCKED_ONLY(t_infomask)))
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_DATA_CORRUPTED),
|
|
errmsg_internal("multixact %u from before cutoff %u found to be still running",
|
|
multi, cutoff_multi)));
|
|
|
|
if (HEAP_XMAX_IS_LOCKED_ONLY(t_infomask))
|
|
{
|
|
*flags |= FRM_INVALIDATE_XMAX;
|
|
xid = InvalidTransactionId; /* not strictly necessary */
|
|
}
|
|
else
|
|
{
|
|
/* replace multi by update xid */
|
|
xid = MultiXactIdGetUpdateXid(multi, t_infomask);
|
|
|
|
/* wasn't only a lock, xid needs to be valid */
|
|
Assert(TransactionIdIsValid(xid));
|
|
|
|
if (TransactionIdPrecedes(xid, relfrozenxid))
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_DATA_CORRUPTED),
|
|
errmsg_internal("found update xid %u from before relfrozenxid %u",
|
|
xid, relfrozenxid)));
|
|
|
|
/*
|
|
* If the xid is older than the cutoff, it has to have aborted,
|
|
* otherwise the tuple would have gotten pruned away.
|
|
*/
|
|
if (TransactionIdPrecedes(xid, cutoff_xid))
|
|
{
|
|
if (TransactionIdDidCommit(xid))
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_DATA_CORRUPTED),
|
|
errmsg_internal("cannot freeze committed update xid %u", xid)));
|
|
*flags |= FRM_INVALIDATE_XMAX;
|
|
xid = InvalidTransactionId; /* not strictly necessary */
|
|
}
|
|
else
|
|
{
|
|
*flags |= FRM_RETURN_IS_XID;
|
|
}
|
|
}
|
|
|
|
return xid;
|
|
}
|
|
|
|
/*
|
|
* This multixact might have or might not have members still running, but
|
|
* we know it's valid and is newer than the cutoff point for multis.
|
|
* However, some member(s) of it may be below the cutoff for Xids, so we
|
|
* need to walk the whole members array to figure out what to do, if
|
|
* anything.
|
|
*/
|
|
|
|
nmembers =
|
|
GetMultiXactIdMembers(multi, &members, false,
|
|
HEAP_XMAX_IS_LOCKED_ONLY(t_infomask));
|
|
if (nmembers <= 0)
|
|
{
|
|
/* Nothing worth keeping */
|
|
*flags |= FRM_INVALIDATE_XMAX;
|
|
return InvalidTransactionId;
|
|
}
|
|
|
|
/* is there anything older than the cutoff? */
|
|
need_replace = false;
|
|
for (i = 0; i < nmembers; i++)
|
|
{
|
|
if (TransactionIdPrecedes(members[i].xid, cutoff_xid))
|
|
{
|
|
need_replace = true;
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* In the simplest case, there is no member older than the cutoff; we can
|
|
* keep the existing MultiXactId as is.
|
|
*/
|
|
if (!need_replace)
|
|
{
|
|
*flags |= FRM_NOOP;
|
|
pfree(members);
|
|
return InvalidTransactionId;
|
|
}
|
|
|
|
/*
|
|
* If the multi needs to be updated, figure out which members do we need
|
|
* to keep.
|
|
*/
|
|
nnewmembers = 0;
|
|
newmembers = palloc(sizeof(MultiXactMember) * nmembers);
|
|
has_lockers = false;
|
|
update_xid = InvalidTransactionId;
|
|
update_committed = false;
|
|
|
|
for (i = 0; i < nmembers; i++)
|
|
{
|
|
/*
|
|
* Determine whether to keep this member or ignore it.
|
|
*/
|
|
if (ISUPDATE_from_mxstatus(members[i].status))
|
|
{
|
|
TransactionId xid = members[i].xid;
|
|
|
|
Assert(TransactionIdIsValid(xid));
|
|
if (TransactionIdPrecedes(xid, relfrozenxid))
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_DATA_CORRUPTED),
|
|
errmsg_internal("found update xid %u from before relfrozenxid %u",
|
|
xid, relfrozenxid)));
|
|
|
|
/*
|
|
* It's an update; should we keep it? If the transaction is known
|
|
* aborted or crashed then it's okay to ignore it, otherwise not.
|
|
* Note that an updater older than cutoff_xid cannot possibly be
|
|
* committed, because HeapTupleSatisfiesVacuum would have returned
|
|
* HEAPTUPLE_DEAD and we would not be trying to freeze the tuple.
|
|
*
|
|
* As with all tuple visibility routines, it's critical to test
|
|
* TransactionIdIsInProgress before TransactionIdDidCommit,
|
|
* because of race conditions explained in detail in tqual.c.
|
|
*/
|
|
if (TransactionIdIsCurrentTransactionId(xid) ||
|
|
TransactionIdIsInProgress(xid))
|
|
{
|
|
Assert(!TransactionIdIsValid(update_xid));
|
|
update_xid = xid;
|
|
}
|
|
else if (TransactionIdDidCommit(xid))
|
|
{
|
|
/*
|
|
* The transaction committed, so we can tell caller to set
|
|
* HEAP_XMAX_COMMITTED. (We can only do this because we know
|
|
* the transaction is not running.)
|
|
*/
|
|
Assert(!TransactionIdIsValid(update_xid));
|
|
update_committed = true;
|
|
update_xid = xid;
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* Not in progress, not committed -- must be aborted or crashed;
|
|
* we can ignore it.
|
|
*/
|
|
}
|
|
|
|
/*
|
|
* Since the tuple wasn't marked HEAPTUPLE_DEAD by vacuum, the
|
|
* update Xid cannot possibly be older than the xid cutoff. The
|
|
* presence of such a tuple would cause corruption, so be paranoid
|
|
* and check.
|
|
*/
|
|
if (TransactionIdIsValid(update_xid) &&
|
|
TransactionIdPrecedes(update_xid, cutoff_xid))
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_DATA_CORRUPTED),
|
|
errmsg_internal("found update xid %u from before xid cutoff %u",
|
|
update_xid, cutoff_xid)));
|
|
|
|
/*
|
|
* If we determined that it's an Xid corresponding to an update
|
|
* that must be retained, additionally add it to the list of
|
|
* members of the new Multi, in case we end up using that. (We
|
|
* might still decide to use only an update Xid and not a multi,
|
|
* but it's easier to maintain the list as we walk the old members
|
|
* list.)
|
|
*/
|
|
if (TransactionIdIsValid(update_xid))
|
|
newmembers[nnewmembers++] = members[i];
|
|
}
|
|
else
|
|
{
|
|
/* We only keep lockers if they are still running */
|
|
if (TransactionIdIsCurrentTransactionId(members[i].xid) ||
|
|
TransactionIdIsInProgress(members[i].xid))
|
|
{
|
|
/* running locker cannot possibly be older than the cutoff */
|
|
Assert(!TransactionIdPrecedes(members[i].xid, cutoff_xid));
|
|
newmembers[nnewmembers++] = members[i];
|
|
has_lockers = true;
|
|
}
|
|
}
|
|
}
|
|
|
|
pfree(members);
|
|
|
|
if (nnewmembers == 0)
|
|
{
|
|
/* nothing worth keeping!? Tell caller to remove the whole thing */
|
|
*flags |= FRM_INVALIDATE_XMAX;
|
|
xid = InvalidTransactionId;
|
|
}
|
|
else if (TransactionIdIsValid(update_xid) && !has_lockers)
|
|
{
|
|
/*
|
|
* If there's a single member and it's an update, pass it back alone
|
|
* without creating a new Multi. (XXX we could do this when there's a
|
|
* single remaining locker, too, but that would complicate the API too
|
|
* much; moreover, the case with the single updater is more
|
|
* interesting, because those are longer-lived.)
|
|
*/
|
|
Assert(nnewmembers == 1);
|
|
*flags |= FRM_RETURN_IS_XID;
|
|
if (update_committed)
|
|
*flags |= FRM_MARK_COMMITTED;
|
|
xid = update_xid;
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* Create a new multixact with the surviving members of the previous
|
|
* one, to set as new Xmax in the tuple.
|
|
*/
|
|
xid = MultiXactIdCreateFromMembers(nnewmembers, newmembers);
|
|
*flags |= FRM_RETURN_IS_MULTI;
|
|
}
|
|
|
|
pfree(newmembers);
|
|
|
|
return xid;
|
|
}
|
|
|
|
/*
|
|
* heap_prepare_freeze_tuple
|
|
*
|
|
* Check to see whether any of the XID fields of a tuple (xmin, xmax, xvac)
|
|
* are older than the specified cutoff XID and cutoff MultiXactId. If so,
|
|
* setup enough state (in the *frz output argument) to later execute and
|
|
* WAL-log what we would need to do, and return true. Return false if nothing
|
|
* is to be changed. In addition, set *totally_frozen_p to true if the tuple
|
|
* will be totally frozen after these operations are performed and false if
|
|
* more freezing will eventually be required.
|
|
*
|
|
* Caller is responsible for setting the offset field, if appropriate.
|
|
*
|
|
* It is assumed that the caller has checked the tuple with
|
|
* HeapTupleSatisfiesVacuum() and determined that it is not HEAPTUPLE_DEAD
|
|
* (else we should be removing the tuple, not freezing it).
|
|
*
|
|
* NB: cutoff_xid *must* be <= the current global xmin, to ensure that any
|
|
* XID older than it could neither be running nor seen as running by any
|
|
* open transaction. This ensures that the replacement will not change
|
|
* anyone's idea of the tuple state.
|
|
* Similarly, cutoff_multi must be less than or equal to the smallest
|
|
* MultiXactId used by any transaction currently open.
|
|
*
|
|
* If the tuple is in a shared buffer, caller must hold an exclusive lock on
|
|
* that buffer.
|
|
*
|
|
* NB: It is not enough to set hint bits to indicate something is
|
|
* committed/invalid -- they might not be set on a standby, or after crash
|
|
* recovery. We really need to remove old xids.
|
|
*/
|
|
bool
|
|
heap_prepare_freeze_tuple(HeapTupleHeader tuple,
|
|
TransactionId relfrozenxid, TransactionId relminmxid,
|
|
TransactionId cutoff_xid, TransactionId cutoff_multi,
|
|
xl_heap_freeze_tuple *frz, bool *totally_frozen_p)
|
|
{
|
|
bool changed = false;
|
|
bool freeze_xmax = false;
|
|
TransactionId xid;
|
|
bool totally_frozen = true;
|
|
|
|
frz->frzflags = 0;
|
|
frz->t_infomask2 = tuple->t_infomask2;
|
|
frz->t_infomask = tuple->t_infomask;
|
|
frz->xmax = HeapTupleHeaderGetRawXmax(tuple);
|
|
|
|
/* Process xmin */
|
|
xid = HeapTupleHeaderGetXmin(tuple);
|
|
if (TransactionIdIsNormal(xid))
|
|
{
|
|
if (TransactionIdPrecedes(xid, relfrozenxid))
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_DATA_CORRUPTED),
|
|
errmsg_internal("found xmin %u from before relfrozenxid %u",
|
|
xid, relfrozenxid)));
|
|
|
|
if (TransactionIdPrecedes(xid, cutoff_xid))
|
|
{
|
|
if (!TransactionIdDidCommit(xid))
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_DATA_CORRUPTED),
|
|
errmsg_internal("uncommitted xmin %u from before xid cutoff %u needs to be frozen",
|
|
xid, cutoff_xid)));
|
|
|
|
frz->t_infomask |= HEAP_XMIN_FROZEN;
|
|
changed = true;
|
|
}
|
|
else
|
|
totally_frozen = false;
|
|
}
|
|
|
|
/*
|
|
* Process xmax. To thoroughly examine the current Xmax value we need to
|
|
* resolve a MultiXactId to its member Xids, in case some of them are
|
|
* below the given cutoff for Xids. In that case, those values might need
|
|
* freezing, too. Also, if a multi needs freezing, we cannot simply take
|
|
* it out --- if there's a live updater Xid, it needs to be kept.
|
|
*
|
|
* Make sure to keep heap_tuple_needs_freeze in sync with this.
|
|
*/
|
|
xid = HeapTupleHeaderGetRawXmax(tuple);
|
|
|
|
if (tuple->t_infomask & HEAP_XMAX_IS_MULTI)
|
|
{
|
|
TransactionId newxmax;
|
|
uint16 flags;
|
|
|
|
newxmax = FreezeMultiXactId(xid, tuple->t_infomask,
|
|
relfrozenxid, relminmxid,
|
|
cutoff_xid, cutoff_multi, &flags);
|
|
|
|
if (flags & FRM_INVALIDATE_XMAX)
|
|
freeze_xmax = true;
|
|
else if (flags & FRM_RETURN_IS_XID)
|
|
{
|
|
/*
|
|
* NB -- some of these transformations are only valid because we
|
|
* know the return Xid is a tuple updater (i.e. not merely a
|
|
* locker.) Also note that the only reason we don't explicitly
|
|
* worry about HEAP_KEYS_UPDATED is because it lives in
|
|
* t_infomask2 rather than t_infomask.
|
|
*/
|
|
frz->t_infomask &= ~HEAP_XMAX_BITS;
|
|
frz->xmax = newxmax;
|
|
if (flags & FRM_MARK_COMMITTED)
|
|
frz->t_infomask |= HEAP_XMAX_COMMITTED;
|
|
changed = true;
|
|
totally_frozen = false;
|
|
}
|
|
else if (flags & FRM_RETURN_IS_MULTI)
|
|
{
|
|
uint16 newbits;
|
|
uint16 newbits2;
|
|
|
|
/*
|
|
* We can't use GetMultiXactIdHintBits directly on the new multi
|
|
* here; that routine initializes the masks to all zeroes, which
|
|
* would lose other bits we need. Doing it this way ensures all
|
|
* unrelated bits remain untouched.
|
|
*/
|
|
frz->t_infomask &= ~HEAP_XMAX_BITS;
|
|
frz->t_infomask2 &= ~HEAP_KEYS_UPDATED;
|
|
GetMultiXactIdHintBits(newxmax, &newbits, &newbits2);
|
|
frz->t_infomask |= newbits;
|
|
frz->t_infomask2 |= newbits2;
|
|
|
|
frz->xmax = newxmax;
|
|
|
|
changed = true;
|
|
totally_frozen = false;
|
|
}
|
|
else
|
|
{
|
|
Assert(flags & FRM_NOOP);
|
|
}
|
|
}
|
|
else if (TransactionIdIsNormal(xid))
|
|
{
|
|
if (TransactionIdPrecedes(xid, relfrozenxid))
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_DATA_CORRUPTED),
|
|
errmsg_internal("found xmax %u from before relfrozenxid %u",
|
|
xid, relfrozenxid)));
|
|
|
|
if (TransactionIdPrecedes(xid, cutoff_xid))
|
|
{
|
|
/*
|
|
* If we freeze xmax, make absolutely sure that it's not an XID
|
|
* that is important. (Note, a lock-only xmax can be removed
|
|
* independent of committedness, since a committed lock holder has
|
|
* released the lock).
|
|
*/
|
|
if (!HEAP_XMAX_IS_LOCKED_ONLY(tuple->t_infomask) &&
|
|
TransactionIdDidCommit(xid))
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_DATA_CORRUPTED),
|
|
errmsg_internal("cannot freeze committed xmax %u",
|
|
xid)));
|
|
freeze_xmax = true;
|
|
}
|
|
else
|
|
totally_frozen = false;
|
|
}
|
|
|
|
if (freeze_xmax)
|
|
{
|
|
frz->xmax = InvalidTransactionId;
|
|
|
|
/*
|
|
* The tuple might be marked either XMAX_INVALID or XMAX_COMMITTED +
|
|
* LOCKED. Normalize to INVALID just to be sure no one gets confused.
|
|
* Also get rid of the HEAP_KEYS_UPDATED bit.
|
|
*/
|
|
frz->t_infomask &= ~HEAP_XMAX_BITS;
|
|
frz->t_infomask |= HEAP_XMAX_INVALID;
|
|
frz->t_infomask2 &= ~HEAP_HOT_UPDATED;
|
|
frz->t_infomask2 &= ~HEAP_KEYS_UPDATED;
|
|
changed = true;
|
|
}
|
|
|
|
/*
|
|
* Old-style VACUUM FULL is gone, but we have to keep this code as long as
|
|
* we support having MOVED_OFF/MOVED_IN tuples in the database.
|
|
*/
|
|
if (tuple->t_infomask & HEAP_MOVED)
|
|
{
|
|
xid = HeapTupleHeaderGetXvac(tuple);
|
|
|
|
/*
|
|
* For Xvac, we ignore the cutoff_xid and just always perform the
|
|
* freeze operation. The oldest release in which such a value can
|
|
* actually be set is PostgreSQL 8.4, because old-style VACUUM FULL
|
|
* was removed in PostgreSQL 9.0. Note that if we were to respect
|
|
* cutoff_xid here, we'd need to make surely to clear totally_frozen
|
|
* when we skipped freezing on that basis.
|
|
*/
|
|
if (TransactionIdIsNormal(xid))
|
|
{
|
|
/*
|
|
* If a MOVED_OFF tuple is not dead, the xvac transaction must
|
|
* have failed; whereas a non-dead MOVED_IN tuple must mean the
|
|
* xvac transaction succeeded.
|
|
*/
|
|
if (tuple->t_infomask & HEAP_MOVED_OFF)
|
|
frz->frzflags |= XLH_INVALID_XVAC;
|
|
else
|
|
frz->frzflags |= XLH_FREEZE_XVAC;
|
|
|
|
/*
|
|
* Might as well fix the hint bits too; usually XMIN_COMMITTED
|
|
* will already be set here, but there's a small chance not.
|
|
*/
|
|
Assert(!(tuple->t_infomask & HEAP_XMIN_INVALID));
|
|
frz->t_infomask |= HEAP_XMIN_COMMITTED;
|
|
changed = true;
|
|
}
|
|
}
|
|
|
|
*totally_frozen_p = totally_frozen;
|
|
return changed;
|
|
}
|
|
|
|
/*
|
|
* heap_execute_freeze_tuple
|
|
* Execute the prepared freezing of a tuple.
|
|
*
|
|
* Caller is responsible for ensuring that no other backend can access the
|
|
* storage underlying this tuple, either by holding an exclusive lock on the
|
|
* buffer containing it (which is what lazy VACUUM does), or by having it be
|
|
* in private storage (which is what CLUSTER and friends do).
|
|
*
|
|
* Note: it might seem we could make the changes without exclusive lock, since
|
|
* TransactionId read/write is assumed atomic anyway. However there is a race
|
|
* condition: someone who just fetched an old XID that we overwrite here could
|
|
* conceivably not finish checking the XID against pg_xact before we finish
|
|
* the VACUUM and perhaps truncate off the part of pg_xact he needs. Getting
|
|
* exclusive lock ensures no other backend is in process of checking the
|
|
* tuple status. Also, getting exclusive lock makes it safe to adjust the
|
|
* infomask bits.
|
|
*
|
|
* NB: All code in here must be safe to execute during crash recovery!
|
|
*/
|
|
void
|
|
heap_execute_freeze_tuple(HeapTupleHeader tuple, xl_heap_freeze_tuple *frz)
|
|
{
|
|
HeapTupleHeaderSetXmax(tuple, frz->xmax);
|
|
|
|
if (frz->frzflags & XLH_FREEZE_XVAC)
|
|
HeapTupleHeaderSetXvac(tuple, FrozenTransactionId);
|
|
|
|
if (frz->frzflags & XLH_INVALID_XVAC)
|
|
HeapTupleHeaderSetXvac(tuple, InvalidTransactionId);
|
|
|
|
tuple->t_infomask = frz->t_infomask;
|
|
tuple->t_infomask2 = frz->t_infomask2;
|
|
}
|
|
|
|
/*
|
|
* heap_freeze_tuple
|
|
* Freeze tuple in place, without WAL logging.
|
|
*
|
|
* Useful for callers like CLUSTER that perform their own WAL logging.
|
|
*/
|
|
bool
|
|
heap_freeze_tuple(HeapTupleHeader tuple,
|
|
TransactionId relfrozenxid, TransactionId relminmxid,
|
|
TransactionId cutoff_xid, TransactionId cutoff_multi)
|
|
{
|
|
xl_heap_freeze_tuple frz;
|
|
bool do_freeze;
|
|
bool tuple_totally_frozen;
|
|
|
|
do_freeze = heap_prepare_freeze_tuple(tuple,
|
|
relfrozenxid, relminmxid,
|
|
cutoff_xid, cutoff_multi,
|
|
&frz, &tuple_totally_frozen);
|
|
|
|
/*
|
|
* Note that because this is not a WAL-logged operation, we don't need to
|
|
* fill in the offset in the freeze record.
|
|
*/
|
|
|
|
if (do_freeze)
|
|
heap_execute_freeze_tuple(tuple, &frz);
|
|
return do_freeze;
|
|
}
|
|
|
|
/*
|
|
* For a given MultiXactId, return the hint bits that should be set in the
|
|
* tuple's infomask.
|
|
*
|
|
* Normally this should be called for a multixact that was just created, and
|
|
* so is on our local cache, so the GetMembers call is fast.
|
|
*/
|
|
static void
|
|
GetMultiXactIdHintBits(MultiXactId multi, uint16 *new_infomask,
|
|
uint16 *new_infomask2)
|
|
{
|
|
int nmembers;
|
|
MultiXactMember *members;
|
|
int i;
|
|
uint16 bits = HEAP_XMAX_IS_MULTI;
|
|
uint16 bits2 = 0;
|
|
bool has_update = false;
|
|
LockTupleMode strongest = LockTupleKeyShare;
|
|
|
|
/*
|
|
* We only use this in multis we just created, so they cannot be values
|
|
* pre-pg_upgrade.
|
|
*/
|
|
nmembers = GetMultiXactIdMembers(multi, &members, false, false);
|
|
|
|
for (i = 0; i < nmembers; i++)
|
|
{
|
|
LockTupleMode mode;
|
|
|
|
/*
|
|
* Remember the strongest lock mode held by any member of the
|
|
* multixact.
|
|
*/
|
|
mode = TUPLOCK_from_mxstatus(members[i].status);
|
|
if (mode > strongest)
|
|
strongest = mode;
|
|
|
|
/* See what other bits we need */
|
|
switch (members[i].status)
|
|
{
|
|
case MultiXactStatusForKeyShare:
|
|
case MultiXactStatusForShare:
|
|
case MultiXactStatusForNoKeyUpdate:
|
|
break;
|
|
|
|
case MultiXactStatusForUpdate:
|
|
bits2 |= HEAP_KEYS_UPDATED;
|
|
break;
|
|
|
|
case MultiXactStatusNoKeyUpdate:
|
|
has_update = true;
|
|
break;
|
|
|
|
case MultiXactStatusUpdate:
|
|
bits2 |= HEAP_KEYS_UPDATED;
|
|
has_update = true;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (strongest == LockTupleExclusive ||
|
|
strongest == LockTupleNoKeyExclusive)
|
|
bits |= HEAP_XMAX_EXCL_LOCK;
|
|
else if (strongest == LockTupleShare)
|
|
bits |= HEAP_XMAX_SHR_LOCK;
|
|
else if (strongest == LockTupleKeyShare)
|
|
bits |= HEAP_XMAX_KEYSHR_LOCK;
|
|
|
|
if (!has_update)
|
|
bits |= HEAP_XMAX_LOCK_ONLY;
|
|
|
|
if (nmembers > 0)
|
|
pfree(members);
|
|
|
|
*new_infomask = bits;
|
|
*new_infomask2 = bits2;
|
|
}
|
|
|
|
/*
|
|
* MultiXactIdGetUpdateXid
|
|
*
|
|
* Given a multixact Xmax and corresponding infomask, which does not have the
|
|
* HEAP_XMAX_LOCK_ONLY bit set, obtain and return the Xid of the updating
|
|
* transaction.
|
|
*
|
|
* Caller is expected to check the status of the updating transaction, if
|
|
* necessary.
|
|
*/
|
|
static TransactionId
|
|
MultiXactIdGetUpdateXid(TransactionId xmax, uint16 t_infomask)
|
|
{
|
|
TransactionId update_xact = InvalidTransactionId;
|
|
MultiXactMember *members;
|
|
int nmembers;
|
|
|
|
Assert(!(t_infomask & HEAP_XMAX_LOCK_ONLY));
|
|
Assert(t_infomask & HEAP_XMAX_IS_MULTI);
|
|
|
|
/*
|
|
* Since we know the LOCK_ONLY bit is not set, this cannot be a multi from
|
|
* pre-pg_upgrade.
|
|
*/
|
|
nmembers = GetMultiXactIdMembers(xmax, &members, false, false);
|
|
|
|
if (nmembers > 0)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < nmembers; i++)
|
|
{
|
|
/* Ignore lockers */
|
|
if (!ISUPDATE_from_mxstatus(members[i].status))
|
|
continue;
|
|
|
|
/* there can be at most one updater */
|
|
Assert(update_xact == InvalidTransactionId);
|
|
update_xact = members[i].xid;
|
|
#ifndef USE_ASSERT_CHECKING
|
|
|
|
/*
|
|
* in an assert-enabled build, walk the whole array to ensure
|
|
* there's no other updater.
|
|
*/
|
|
break;
|
|
#endif
|
|
}
|
|
|
|
pfree(members);
|
|
}
|
|
|
|
return update_xact;
|
|
}
|
|
|
|
/*
|
|
* HeapTupleGetUpdateXid
|
|
* As above, but use a HeapTupleHeader
|
|
*
|
|
* See also HeapTupleHeaderGetUpdateXid, which can be used without previously
|
|
* checking the hint bits.
|
|
*/
|
|
TransactionId
|
|
HeapTupleGetUpdateXid(HeapTupleHeader tuple)
|
|
{
|
|
return MultiXactIdGetUpdateXid(HeapTupleHeaderGetRawXmax(tuple),
|
|
tuple->t_infomask);
|
|
}
|
|
|
|
/*
|
|
* Does the given multixact conflict with the current transaction grabbing a
|
|
* tuple lock of the given strength?
|
|
*
|
|
* The passed infomask pairs up with the given multixact in the tuple header.
|
|
*/
|
|
static bool
|
|
DoesMultiXactIdConflict(MultiXactId multi, uint16 infomask,
|
|
LockTupleMode lockmode)
|
|
{
|
|
int nmembers;
|
|
MultiXactMember *members;
|
|
bool result = false;
|
|
LOCKMODE wanted = tupleLockExtraInfo[lockmode].hwlock;
|
|
|
|
if (HEAP_LOCKED_UPGRADED(infomask))
|
|
return false;
|
|
|
|
nmembers = GetMultiXactIdMembers(multi, &members, false,
|
|
HEAP_XMAX_IS_LOCKED_ONLY(infomask));
|
|
if (nmembers >= 0)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < nmembers; i++)
|
|
{
|
|
TransactionId memxid;
|
|
LOCKMODE memlockmode;
|
|
|
|
memlockmode = LOCKMODE_from_mxstatus(members[i].status);
|
|
|
|
/* ignore members that don't conflict with the lock we want */
|
|
if (!DoLockModesConflict(memlockmode, wanted))
|
|
continue;
|
|
|
|
/* ignore members from current xact */
|
|
memxid = members[i].xid;
|
|
if (TransactionIdIsCurrentTransactionId(memxid))
|
|
continue;
|
|
|
|
if (ISUPDATE_from_mxstatus(members[i].status))
|
|
{
|
|
/* ignore aborted updaters */
|
|
if (TransactionIdDidAbort(memxid))
|
|
continue;
|
|
}
|
|
else
|
|
{
|
|
/* ignore lockers-only that are no longer in progress */
|
|
if (!TransactionIdIsInProgress(memxid))
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* Whatever remains are either live lockers that conflict with our
|
|
* wanted lock, and updaters that are not aborted. Those conflict
|
|
* with what we want, so return true.
|
|
*/
|
|
result = true;
|
|
break;
|
|
}
|
|
pfree(members);
|
|
}
|
|
|
|
return result;
|
|
}
|
|
|
|
/*
|
|
* Do_MultiXactIdWait
|
|
* Actual implementation for the two functions below.
|
|
*
|
|
* 'multi', 'status' and 'infomask' indicate what to sleep on (the status is
|
|
* needed to ensure we only sleep on conflicting members, and the infomask is
|
|
* used to optimize multixact access in case it's a lock-only multi); 'nowait'
|
|
* indicates whether to use conditional lock acquisition, to allow callers to
|
|
* fail if lock is unavailable. 'rel', 'ctid' and 'oper' are used to set up
|
|
* context information for error messages. 'remaining', if not NULL, receives
|
|
* the number of members that are still running, including any (non-aborted)
|
|
* subtransactions of our own transaction.
|
|
*
|
|
* We do this by sleeping on each member using XactLockTableWait. Any
|
|
* members that belong to the current backend are *not* waited for, however;
|
|
* this would not merely be useless but would lead to Assert failure inside
|
|
* XactLockTableWait. By the time this returns, it is certain that all
|
|
* transactions *of other backends* that were members of the MultiXactId
|
|
* that conflict with the requested status are dead (and no new ones can have
|
|
* been added, since it is not legal to add members to an existing
|
|
* MultiXactId).
|
|
*
|
|
* But by the time we finish sleeping, someone else may have changed the Xmax
|
|
* of the containing tuple, so the caller needs to iterate on us somehow.
|
|
*
|
|
* Note that in case we return false, the number of remaining members is
|
|
* not to be trusted.
|
|
*/
|
|
static bool
|
|
Do_MultiXactIdWait(MultiXactId multi, MultiXactStatus status,
|
|
uint16 infomask, bool nowait,
|
|
Relation rel, ItemPointer ctid, XLTW_Oper oper,
|
|
int *remaining)
|
|
{
|
|
bool result = true;
|
|
MultiXactMember *members;
|
|
int nmembers;
|
|
int remain = 0;
|
|
|
|
/* for pre-pg_upgrade tuples, no need to sleep at all */
|
|
nmembers = HEAP_LOCKED_UPGRADED(infomask) ? -1 :
|
|
GetMultiXactIdMembers(multi, &members, false,
|
|
HEAP_XMAX_IS_LOCKED_ONLY(infomask));
|
|
|
|
if (nmembers >= 0)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < nmembers; i++)
|
|
{
|
|
TransactionId memxid = members[i].xid;
|
|
MultiXactStatus memstatus = members[i].status;
|
|
|
|
if (TransactionIdIsCurrentTransactionId(memxid))
|
|
{
|
|
remain++;
|
|
continue;
|
|
}
|
|
|
|
if (!DoLockModesConflict(LOCKMODE_from_mxstatus(memstatus),
|
|
LOCKMODE_from_mxstatus(status)))
|
|
{
|
|
if (remaining && TransactionIdIsInProgress(memxid))
|
|
remain++;
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* This member conflicts with our multi, so we have to sleep (or
|
|
* return failure, if asked to avoid waiting.)
|
|
*
|
|
* Note that we don't set up an error context callback ourselves,
|
|
* but instead we pass the info down to XactLockTableWait. This
|
|
* might seem a bit wasteful because the context is set up and
|
|
* tore down for each member of the multixact, but in reality it
|
|
* should be barely noticeable, and it avoids duplicate code.
|
|
*/
|
|
if (nowait)
|
|
{
|
|
result = ConditionalXactLockTableWait(memxid);
|
|
if (!result)
|
|
break;
|
|
}
|
|
else
|
|
XactLockTableWait(memxid, rel, ctid, oper);
|
|
}
|
|
|
|
pfree(members);
|
|
}
|
|
|
|
if (remaining)
|
|
*remaining = remain;
|
|
|
|
return result;
|
|
}
|
|
|
|
/*
|
|
* MultiXactIdWait
|
|
* Sleep on a MultiXactId.
|
|
*
|
|
* By the time we finish sleeping, someone else may have changed the Xmax
|
|
* of the containing tuple, so the caller needs to iterate on us somehow.
|
|
*
|
|
* We return (in *remaining, if not NULL) the number of members that are still
|
|
* running, including any (non-aborted) subtransactions of our own transaction.
|
|
*/
|
|
static void
|
|
MultiXactIdWait(MultiXactId multi, MultiXactStatus status, uint16 infomask,
|
|
Relation rel, ItemPointer ctid, XLTW_Oper oper,
|
|
int *remaining)
|
|
{
|
|
(void) Do_MultiXactIdWait(multi, status, infomask, false,
|
|
rel, ctid, oper, remaining);
|
|
}
|
|
|
|
/*
|
|
* ConditionalMultiXactIdWait
|
|
* As above, but only lock if we can get the lock without blocking.
|
|
*
|
|
* By the time we finish sleeping, someone else may have changed the Xmax
|
|
* of the containing tuple, so the caller needs to iterate on us somehow.
|
|
*
|
|
* If the multixact is now all gone, return true. Returns false if some
|
|
* transactions might still be running.
|
|
*
|
|
* We return (in *remaining, if not NULL) the number of members that are still
|
|
* running, including any (non-aborted) subtransactions of our own transaction.
|
|
*/
|
|
static bool
|
|
ConditionalMultiXactIdWait(MultiXactId multi, MultiXactStatus status,
|
|
uint16 infomask, Relation rel, int *remaining)
|
|
{
|
|
return Do_MultiXactIdWait(multi, status, infomask, true,
|
|
rel, NULL, XLTW_None, remaining);
|
|
}
|
|
|
|
/*
|
|
* heap_tuple_needs_eventual_freeze
|
|
*
|
|
* Check to see whether any of the XID fields of a tuple (xmin, xmax, xvac)
|
|
* will eventually require freezing. Similar to heap_tuple_needs_freeze,
|
|
* but there's no cutoff, since we're trying to figure out whether freezing
|
|
* will ever be needed, not whether it's needed now.
|
|
*/
|
|
bool
|
|
heap_tuple_needs_eventual_freeze(HeapTupleHeader tuple)
|
|
{
|
|
TransactionId xid;
|
|
|
|
/*
|
|
* If xmin is a normal transaction ID, this tuple is definitely not
|
|
* frozen.
|
|
*/
|
|
xid = HeapTupleHeaderGetXmin(tuple);
|
|
if (TransactionIdIsNormal(xid))
|
|
return true;
|
|
|
|
/*
|
|
* If xmax is a valid xact or multixact, this tuple is also not frozen.
|
|
*/
|
|
if (tuple->t_infomask & HEAP_XMAX_IS_MULTI)
|
|
{
|
|
MultiXactId multi;
|
|
|
|
multi = HeapTupleHeaderGetRawXmax(tuple);
|
|
if (MultiXactIdIsValid(multi))
|
|
return true;
|
|
}
|
|
else
|
|
{
|
|
xid = HeapTupleHeaderGetRawXmax(tuple);
|
|
if (TransactionIdIsNormal(xid))
|
|
return true;
|
|
}
|
|
|
|
if (tuple->t_infomask & HEAP_MOVED)
|
|
{
|
|
xid = HeapTupleHeaderGetXvac(tuple);
|
|
if (TransactionIdIsNormal(xid))
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* heap_tuple_needs_freeze
|
|
*
|
|
* Check to see whether any of the XID fields of a tuple (xmin, xmax, xvac)
|
|
* are older than the specified cutoff XID or MultiXactId. If so, return true.
|
|
*
|
|
* It doesn't matter whether the tuple is alive or dead, we are checking
|
|
* to see if a tuple needs to be removed or frozen to avoid wraparound.
|
|
*
|
|
* NB: Cannot rely on hint bits here, they might not be set after a crash or
|
|
* on a standby.
|
|
*/
|
|
bool
|
|
heap_tuple_needs_freeze(HeapTupleHeader tuple, TransactionId cutoff_xid,
|
|
MultiXactId cutoff_multi, Buffer buf)
|
|
{
|
|
TransactionId xid;
|
|
|
|
xid = HeapTupleHeaderGetXmin(tuple);
|
|
if (TransactionIdIsNormal(xid) &&
|
|
TransactionIdPrecedes(xid, cutoff_xid))
|
|
return true;
|
|
|
|
/*
|
|
* The considerations for multixacts are complicated; look at
|
|
* heap_prepare_freeze_tuple for justifications. This routine had better
|
|
* be in sync with that one!
|
|
*/
|
|
if (tuple->t_infomask & HEAP_XMAX_IS_MULTI)
|
|
{
|
|
MultiXactId multi;
|
|
|
|
multi = HeapTupleHeaderGetRawXmax(tuple);
|
|
if (!MultiXactIdIsValid(multi))
|
|
{
|
|
/* no xmax set, ignore */
|
|
;
|
|
}
|
|
else if (HEAP_LOCKED_UPGRADED(tuple->t_infomask))
|
|
return true;
|
|
else if (MultiXactIdPrecedes(multi, cutoff_multi))
|
|
return true;
|
|
else
|
|
{
|
|
MultiXactMember *members;
|
|
int nmembers;
|
|
int i;
|
|
|
|
/* need to check whether any member of the mxact is too old */
|
|
|
|
nmembers = GetMultiXactIdMembers(multi, &members, false,
|
|
HEAP_XMAX_IS_LOCKED_ONLY(tuple->t_infomask));
|
|
|
|
for (i = 0; i < nmembers; i++)
|
|
{
|
|
if (TransactionIdPrecedes(members[i].xid, cutoff_xid))
|
|
{
|
|
pfree(members);
|
|
return true;
|
|
}
|
|
}
|
|
if (nmembers > 0)
|
|
pfree(members);
|
|
}
|
|
}
|
|
else
|
|
{
|
|
xid = HeapTupleHeaderGetRawXmax(tuple);
|
|
if (TransactionIdIsNormal(xid) &&
|
|
TransactionIdPrecedes(xid, cutoff_xid))
|
|
return true;
|
|
}
|
|
|
|
if (tuple->t_infomask & HEAP_MOVED)
|
|
{
|
|
xid = HeapTupleHeaderGetXvac(tuple);
|
|
if (TransactionIdIsNormal(xid) &&
|
|
TransactionIdPrecedes(xid, cutoff_xid))
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* If 'tuple' contains any visible XID greater than latestRemovedXid,
|
|
* ratchet forwards latestRemovedXid to the greatest one found.
|
|
* This is used as the basis for generating Hot Standby conflicts, so
|
|
* if a tuple was never visible then removing it should not conflict
|
|
* with queries.
|
|
*/
|
|
void
|
|
HeapTupleHeaderAdvanceLatestRemovedXid(HeapTupleHeader tuple,
|
|
TransactionId *latestRemovedXid)
|
|
{
|
|
TransactionId xmin = HeapTupleHeaderGetXmin(tuple);
|
|
TransactionId xmax = HeapTupleHeaderGetUpdateXid(tuple);
|
|
TransactionId xvac = HeapTupleHeaderGetXvac(tuple);
|
|
|
|
if (tuple->t_infomask & HEAP_MOVED)
|
|
{
|
|
if (TransactionIdPrecedes(*latestRemovedXid, xvac))
|
|
*latestRemovedXid = xvac;
|
|
}
|
|
|
|
/*
|
|
* Ignore tuples inserted by an aborted transaction or if the tuple was
|
|
* updated/deleted by the inserting transaction.
|
|
*
|
|
* Look for a committed hint bit, or if no xmin bit is set, check clog.
|
|
* This needs to work on both master and standby, where it is used to
|
|
* assess btree delete records.
|
|
*/
|
|
if (HeapTupleHeaderXminCommitted(tuple) ||
|
|
(!HeapTupleHeaderXminInvalid(tuple) && TransactionIdDidCommit(xmin)))
|
|
{
|
|
if (xmax != xmin &&
|
|
TransactionIdFollows(xmax, *latestRemovedXid))
|
|
*latestRemovedXid = xmax;
|
|
}
|
|
|
|
/* *latestRemovedXid may still be invalid at end */
|
|
}
|
|
|
|
/*
|
|
* Perform XLogInsert to register a heap cleanup info message. These
|
|
* messages are sent once per VACUUM and are required because
|
|
* of the phasing of removal operations during a lazy VACUUM.
|
|
* see comments for vacuum_log_cleanup_info().
|
|
*/
|
|
XLogRecPtr
|
|
log_heap_cleanup_info(RelFileNode rnode, TransactionId latestRemovedXid)
|
|
{
|
|
xl_heap_cleanup_info xlrec;
|
|
XLogRecPtr recptr;
|
|
|
|
xlrec.node = rnode;
|
|
xlrec.latestRemovedXid = latestRemovedXid;
|
|
|
|
XLogBeginInsert();
|
|
XLogRegisterData((char *) &xlrec, SizeOfHeapCleanupInfo);
|
|
|
|
recptr = XLogInsert(RM_HEAP2_ID, XLOG_HEAP2_CLEANUP_INFO);
|
|
|
|
return recptr;
|
|
}
|
|
|
|
/*
|
|
* Perform XLogInsert for a heap-clean operation. Caller must already
|
|
* have modified the buffer and marked it dirty.
|
|
*
|
|
* Note: prior to Postgres 8.3, the entries in the nowunused[] array were
|
|
* zero-based tuple indexes. Now they are one-based like other uses
|
|
* of OffsetNumber.
|
|
*
|
|
* We also include latestRemovedXid, which is the greatest XID present in
|
|
* the removed tuples. That allows recovery processing to cancel or wait
|
|
* for long standby queries that can still see these tuples.
|
|
*/
|
|
XLogRecPtr
|
|
log_heap_clean(Relation reln, Buffer buffer,
|
|
OffsetNumber *redirected, int nredirected,
|
|
OffsetNumber *nowdead, int ndead,
|
|
OffsetNumber *nowunused, int nunused,
|
|
TransactionId latestRemovedXid)
|
|
{
|
|
xl_heap_clean xlrec;
|
|
XLogRecPtr recptr;
|
|
|
|
/* Caller should not call me on a non-WAL-logged relation */
|
|
Assert(RelationNeedsWAL(reln));
|
|
|
|
xlrec.latestRemovedXid = latestRemovedXid;
|
|
xlrec.nredirected = nredirected;
|
|
xlrec.ndead = ndead;
|
|
|
|
XLogBeginInsert();
|
|
XLogRegisterData((char *) &xlrec, SizeOfHeapClean);
|
|
|
|
XLogRegisterBuffer(0, buffer, REGBUF_STANDARD);
|
|
|
|
/*
|
|
* The OffsetNumber arrays are not actually in the buffer, but we pretend
|
|
* that they are. When XLogInsert stores the whole buffer, the offset
|
|
* arrays need not be stored too. Note that even if all three arrays are
|
|
* empty, we want to expose the buffer as a candidate for whole-page
|
|
* storage, since this record type implies a defragmentation operation
|
|
* even if no item pointers changed state.
|
|
*/
|
|
if (nredirected > 0)
|
|
XLogRegisterBufData(0, (char *) redirected,
|
|
nredirected * sizeof(OffsetNumber) * 2);
|
|
|
|
if (ndead > 0)
|
|
XLogRegisterBufData(0, (char *) nowdead,
|
|
ndead * sizeof(OffsetNumber));
|
|
|
|
if (nunused > 0)
|
|
XLogRegisterBufData(0, (char *) nowunused,
|
|
nunused * sizeof(OffsetNumber));
|
|
|
|
recptr = XLogInsert(RM_HEAP2_ID, XLOG_HEAP2_CLEAN);
|
|
|
|
return recptr;
|
|
}
|
|
|
|
/*
|
|
* Perform XLogInsert for a heap-freeze operation. Caller must have already
|
|
* modified the buffer and marked it dirty.
|
|
*/
|
|
XLogRecPtr
|
|
log_heap_freeze(Relation reln, Buffer buffer, TransactionId cutoff_xid,
|
|
xl_heap_freeze_tuple *tuples, int ntuples)
|
|
{
|
|
xl_heap_freeze_page xlrec;
|
|
XLogRecPtr recptr;
|
|
|
|
/* Caller should not call me on a non-WAL-logged relation */
|
|
Assert(RelationNeedsWAL(reln));
|
|
/* nor when there are no tuples to freeze */
|
|
Assert(ntuples > 0);
|
|
|
|
xlrec.cutoff_xid = cutoff_xid;
|
|
xlrec.ntuples = ntuples;
|
|
|
|
XLogBeginInsert();
|
|
XLogRegisterData((char *) &xlrec, SizeOfHeapFreezePage);
|
|
|
|
/*
|
|
* The freeze plan array is not actually in the buffer, but pretend that
|
|
* it is. When XLogInsert stores the whole buffer, the freeze plan need
|
|
* not be stored too.
|
|
*/
|
|
XLogRegisterBuffer(0, buffer, REGBUF_STANDARD);
|
|
XLogRegisterBufData(0, (char *) tuples,
|
|
ntuples * sizeof(xl_heap_freeze_tuple));
|
|
|
|
recptr = XLogInsert(RM_HEAP2_ID, XLOG_HEAP2_FREEZE_PAGE);
|
|
|
|
return recptr;
|
|
}
|
|
|
|
/*
|
|
* Perform XLogInsert for a heap-visible operation. 'block' is the block
|
|
* being marked all-visible, and vm_buffer is the buffer containing the
|
|
* corresponding visibility map block. Both should have already been modified
|
|
* and dirtied.
|
|
*
|
|
* If checksums are enabled, we also generate a full-page image of
|
|
* heap_buffer, if necessary.
|
|
*/
|
|
XLogRecPtr
|
|
log_heap_visible(RelFileNode rnode, Buffer heap_buffer, Buffer vm_buffer,
|
|
TransactionId cutoff_xid, uint8 vmflags)
|
|
{
|
|
xl_heap_visible xlrec;
|
|
XLogRecPtr recptr;
|
|
uint8 flags;
|
|
|
|
Assert(BufferIsValid(heap_buffer));
|
|
Assert(BufferIsValid(vm_buffer));
|
|
|
|
xlrec.cutoff_xid = cutoff_xid;
|
|
xlrec.flags = vmflags;
|
|
XLogBeginInsert();
|
|
XLogRegisterData((char *) &xlrec, SizeOfHeapVisible);
|
|
|
|
XLogRegisterBuffer(0, vm_buffer, 0);
|
|
|
|
flags = REGBUF_STANDARD;
|
|
if (!XLogHintBitIsNeeded())
|
|
flags |= REGBUF_NO_IMAGE;
|
|
XLogRegisterBuffer(1, heap_buffer, flags);
|
|
|
|
recptr = XLogInsert(RM_HEAP2_ID, XLOG_HEAP2_VISIBLE);
|
|
|
|
return recptr;
|
|
}
|
|
|
|
/*
|
|
* Perform XLogInsert for a heap-update operation. Caller must already
|
|
* have modified the buffer(s) and marked them dirty.
|
|
*/
|
|
static XLogRecPtr
|
|
log_heap_update(Relation reln, Buffer oldbuf,
|
|
Buffer newbuf, HeapTuple oldtup, HeapTuple newtup,
|
|
HeapTuple old_key_tuple,
|
|
bool all_visible_cleared, bool new_all_visible_cleared)
|
|
{
|
|
xl_heap_update xlrec;
|
|
xl_heap_header xlhdr;
|
|
xl_heap_header xlhdr_idx;
|
|
uint8 info;
|
|
uint16 prefix_suffix[2];
|
|
uint16 prefixlen = 0,
|
|
suffixlen = 0;
|
|
XLogRecPtr recptr;
|
|
Page page = BufferGetPage(newbuf);
|
|
bool need_tuple_data = RelationIsLogicallyLogged(reln);
|
|
bool init;
|
|
int bufflags;
|
|
|
|
/* Caller should not call me on a non-WAL-logged relation */
|
|
Assert(RelationNeedsWAL(reln));
|
|
|
|
XLogBeginInsert();
|
|
|
|
if (HeapTupleIsHeapOnly(newtup))
|
|
info = XLOG_HEAP_HOT_UPDATE;
|
|
else
|
|
info = XLOG_HEAP_UPDATE;
|
|
|
|
/*
|
|
* If the old and new tuple are on the same page, we only need to log the
|
|
* parts of the new tuple that were changed. That saves on the amount of
|
|
* WAL we need to write. Currently, we just count any unchanged bytes in
|
|
* the beginning and end of the tuple. That's quick to check, and
|
|
* perfectly covers the common case that only one field is updated.
|
|
*
|
|
* We could do this even if the old and new tuple are on different pages,
|
|
* but only if we don't make a full-page image of the old page, which is
|
|
* difficult to know in advance. Also, if the old tuple is corrupt for
|
|
* some reason, it would allow the corruption to propagate the new page,
|
|
* so it seems best to avoid. Under the general assumption that most
|
|
* updates tend to create the new tuple version on the same page, there
|
|
* isn't much to be gained by doing this across pages anyway.
|
|
*
|
|
* Skip this if we're taking a full-page image of the new page, as we
|
|
* don't include the new tuple in the WAL record in that case. Also
|
|
* disable if wal_level='logical', as logical decoding needs to be able to
|
|
* read the new tuple in whole from the WAL record alone.
|
|
*/
|
|
if (oldbuf == newbuf && !need_tuple_data &&
|
|
!XLogCheckBufferNeedsBackup(newbuf))
|
|
{
|
|
char *oldp = (char *) oldtup->t_data + oldtup->t_data->t_hoff;
|
|
char *newp = (char *) newtup->t_data + newtup->t_data->t_hoff;
|
|
int oldlen = oldtup->t_len - oldtup->t_data->t_hoff;
|
|
int newlen = newtup->t_len - newtup->t_data->t_hoff;
|
|
|
|
/* Check for common prefix between old and new tuple */
|
|
for (prefixlen = 0; prefixlen < Min(oldlen, newlen); prefixlen++)
|
|
{
|
|
if (newp[prefixlen] != oldp[prefixlen])
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* Storing the length of the prefix takes 2 bytes, so we need to save
|
|
* at least 3 bytes or there's no point.
|
|
*/
|
|
if (prefixlen < 3)
|
|
prefixlen = 0;
|
|
|
|
/* Same for suffix */
|
|
for (suffixlen = 0; suffixlen < Min(oldlen, newlen) - prefixlen; suffixlen++)
|
|
{
|
|
if (newp[newlen - suffixlen - 1] != oldp[oldlen - suffixlen - 1])
|
|
break;
|
|
}
|
|
if (suffixlen < 3)
|
|
suffixlen = 0;
|
|
}
|
|
|
|
/* Prepare main WAL data chain */
|
|
xlrec.flags = 0;
|
|
if (all_visible_cleared)
|
|
xlrec.flags |= XLH_UPDATE_OLD_ALL_VISIBLE_CLEARED;
|
|
if (new_all_visible_cleared)
|
|
xlrec.flags |= XLH_UPDATE_NEW_ALL_VISIBLE_CLEARED;
|
|
if (prefixlen > 0)
|
|
xlrec.flags |= XLH_UPDATE_PREFIX_FROM_OLD;
|
|
if (suffixlen > 0)
|
|
xlrec.flags |= XLH_UPDATE_SUFFIX_FROM_OLD;
|
|
if (need_tuple_data)
|
|
{
|
|
xlrec.flags |= XLH_UPDATE_CONTAINS_NEW_TUPLE;
|
|
if (old_key_tuple)
|
|
{
|
|
if (reln->rd_rel->relreplident == REPLICA_IDENTITY_FULL)
|
|
xlrec.flags |= XLH_UPDATE_CONTAINS_OLD_TUPLE;
|
|
else
|
|
xlrec.flags |= XLH_UPDATE_CONTAINS_OLD_KEY;
|
|
}
|
|
}
|
|
|
|
/* If new tuple is the single and first tuple on page... */
|
|
if (ItemPointerGetOffsetNumber(&(newtup->t_self)) == FirstOffsetNumber &&
|
|
PageGetMaxOffsetNumber(page) == FirstOffsetNumber)
|
|
{
|
|
info |= XLOG_HEAP_INIT_PAGE;
|
|
init = true;
|
|
}
|
|
else
|
|
init = false;
|
|
|
|
/* Prepare WAL data for the old page */
|
|
xlrec.old_offnum = ItemPointerGetOffsetNumber(&oldtup->t_self);
|
|
xlrec.old_xmax = HeapTupleHeaderGetRawXmax(oldtup->t_data);
|
|
xlrec.old_infobits_set = compute_infobits(oldtup->t_data->t_infomask,
|
|
oldtup->t_data->t_infomask2);
|
|
|
|
/* Prepare WAL data for the new page */
|
|
xlrec.new_offnum = ItemPointerGetOffsetNumber(&newtup->t_self);
|
|
xlrec.new_xmax = HeapTupleHeaderGetRawXmax(newtup->t_data);
|
|
|
|
bufflags = REGBUF_STANDARD;
|
|
if (init)
|
|
bufflags |= REGBUF_WILL_INIT;
|
|
if (need_tuple_data)
|
|
bufflags |= REGBUF_KEEP_DATA;
|
|
|
|
XLogRegisterBuffer(0, newbuf, bufflags);
|
|
if (oldbuf != newbuf)
|
|
XLogRegisterBuffer(1, oldbuf, REGBUF_STANDARD);
|
|
|
|
XLogRegisterData((char *) &xlrec, SizeOfHeapUpdate);
|
|
|
|
/*
|
|
* Prepare WAL data for the new tuple.
|
|
*/
|
|
if (prefixlen > 0 || suffixlen > 0)
|
|
{
|
|
if (prefixlen > 0 && suffixlen > 0)
|
|
{
|
|
prefix_suffix[0] = prefixlen;
|
|
prefix_suffix[1] = suffixlen;
|
|
XLogRegisterBufData(0, (char *) &prefix_suffix, sizeof(uint16) * 2);
|
|
}
|
|
else if (prefixlen > 0)
|
|
{
|
|
XLogRegisterBufData(0, (char *) &prefixlen, sizeof(uint16));
|
|
}
|
|
else
|
|
{
|
|
XLogRegisterBufData(0, (char *) &suffixlen, sizeof(uint16));
|
|
}
|
|
}
|
|
|
|
xlhdr.t_infomask2 = newtup->t_data->t_infomask2;
|
|
xlhdr.t_infomask = newtup->t_data->t_infomask;
|
|
xlhdr.t_hoff = newtup->t_data->t_hoff;
|
|
Assert(SizeofHeapTupleHeader + prefixlen + suffixlen <= newtup->t_len);
|
|
|
|
/*
|
|
* PG73FORMAT: write bitmap [+ padding] [+ oid] + data
|
|
*
|
|
* The 'data' doesn't include the common prefix or suffix.
|
|
*/
|
|
XLogRegisterBufData(0, (char *) &xlhdr, SizeOfHeapHeader);
|
|
if (prefixlen == 0)
|
|
{
|
|
XLogRegisterBufData(0,
|
|
((char *) newtup->t_data) + SizeofHeapTupleHeader,
|
|
newtup->t_len - SizeofHeapTupleHeader - suffixlen);
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* Have to write the null bitmap and data after the common prefix as
|
|
* two separate rdata entries.
|
|
*/
|
|
/* bitmap [+ padding] [+ oid] */
|
|
if (newtup->t_data->t_hoff - SizeofHeapTupleHeader > 0)
|
|
{
|
|
XLogRegisterBufData(0,
|
|
((char *) newtup->t_data) + SizeofHeapTupleHeader,
|
|
newtup->t_data->t_hoff - SizeofHeapTupleHeader);
|
|
}
|
|
|
|
/* data after common prefix */
|
|
XLogRegisterBufData(0,
|
|
((char *) newtup->t_data) + newtup->t_data->t_hoff + prefixlen,
|
|
newtup->t_len - newtup->t_data->t_hoff - prefixlen - suffixlen);
|
|
}
|
|
|
|
/* We need to log a tuple identity */
|
|
if (need_tuple_data && old_key_tuple)
|
|
{
|
|
/* don't really need this, but its more comfy to decode */
|
|
xlhdr_idx.t_infomask2 = old_key_tuple->t_data->t_infomask2;
|
|
xlhdr_idx.t_infomask = old_key_tuple->t_data->t_infomask;
|
|
xlhdr_idx.t_hoff = old_key_tuple->t_data->t_hoff;
|
|
|
|
XLogRegisterData((char *) &xlhdr_idx, SizeOfHeapHeader);
|
|
|
|
/* PG73FORMAT: write bitmap [+ padding] [+ oid] + data */
|
|
XLogRegisterData((char *) old_key_tuple->t_data + SizeofHeapTupleHeader,
|
|
old_key_tuple->t_len - SizeofHeapTupleHeader);
|
|
}
|
|
|
|
/* filtering by origin on a row level is much more efficient */
|
|
XLogSetRecordFlags(XLOG_INCLUDE_ORIGIN);
|
|
|
|
recptr = XLogInsert(RM_HEAP_ID, info);
|
|
|
|
return recptr;
|
|
}
|
|
|
|
/*
|
|
* Perform XLogInsert of an XLOG_HEAP2_NEW_CID record
|
|
*
|
|
* This is only used in wal_level >= WAL_LEVEL_LOGICAL, and only for catalog
|
|
* tuples.
|
|
*/
|
|
static XLogRecPtr
|
|
log_heap_new_cid(Relation relation, HeapTuple tup)
|
|
{
|
|
xl_heap_new_cid xlrec;
|
|
|
|
XLogRecPtr recptr;
|
|
HeapTupleHeader hdr = tup->t_data;
|
|
|
|
Assert(ItemPointerIsValid(&tup->t_self));
|
|
Assert(tup->t_tableOid != InvalidOid);
|
|
|
|
xlrec.top_xid = GetTopTransactionId();
|
|
xlrec.target_node = relation->rd_node;
|
|
xlrec.target_tid = tup->t_self;
|
|
|
|
/*
|
|
* If the tuple got inserted & deleted in the same TX we definitely have a
|
|
* combocid, set cmin and cmax.
|
|
*/
|
|
if (hdr->t_infomask & HEAP_COMBOCID)
|
|
{
|
|
Assert(!(hdr->t_infomask & HEAP_XMAX_INVALID));
|
|
Assert(!HeapTupleHeaderXminInvalid(hdr));
|
|
xlrec.cmin = HeapTupleHeaderGetCmin(hdr);
|
|
xlrec.cmax = HeapTupleHeaderGetCmax(hdr);
|
|
xlrec.combocid = HeapTupleHeaderGetRawCommandId(hdr);
|
|
}
|
|
/* No combocid, so only cmin or cmax can be set by this TX */
|
|
else
|
|
{
|
|
/*
|
|
* Tuple inserted.
|
|
*
|
|
* We need to check for LOCK ONLY because multixacts might be
|
|
* transferred to the new tuple in case of FOR KEY SHARE updates in
|
|
* which case there will be an xmax, although the tuple just got
|
|
* inserted.
|
|
*/
|
|
if (hdr->t_infomask & HEAP_XMAX_INVALID ||
|
|
HEAP_XMAX_IS_LOCKED_ONLY(hdr->t_infomask))
|
|
{
|
|
xlrec.cmin = HeapTupleHeaderGetRawCommandId(hdr);
|
|
xlrec.cmax = InvalidCommandId;
|
|
}
|
|
/* Tuple from a different tx updated or deleted. */
|
|
else
|
|
{
|
|
xlrec.cmin = InvalidCommandId;
|
|
xlrec.cmax = HeapTupleHeaderGetRawCommandId(hdr);
|
|
|
|
}
|
|
xlrec.combocid = InvalidCommandId;
|
|
}
|
|
|
|
/*
|
|
* Note that we don't need to register the buffer here, because this
|
|
* operation does not modify the page. The insert/update/delete that
|
|
* called us certainly did, but that's WAL-logged separately.
|
|
*/
|
|
XLogBeginInsert();
|
|
XLogRegisterData((char *) &xlrec, SizeOfHeapNewCid);
|
|
|
|
/* will be looked at irrespective of origin */
|
|
|
|
recptr = XLogInsert(RM_HEAP2_ID, XLOG_HEAP2_NEW_CID);
|
|
|
|
return recptr;
|
|
}
|
|
|
|
/*
|
|
* Build a heap tuple representing the configured REPLICA IDENTITY to represent
|
|
* the old tuple in a UPDATE or DELETE.
|
|
*
|
|
* Returns NULL if there's no need to log an identity or if there's no suitable
|
|
* key in the Relation relation.
|
|
*/
|
|
static HeapTuple
|
|
ExtractReplicaIdentity(Relation relation, HeapTuple tp, bool key_changed, bool *copy)
|
|
{
|
|
TupleDesc desc = RelationGetDescr(relation);
|
|
Oid replidindex;
|
|
Relation idx_rel;
|
|
TupleDesc idx_desc;
|
|
char replident = relation->rd_rel->relreplident;
|
|
HeapTuple key_tuple = NULL;
|
|
bool nulls[MaxHeapAttributeNumber];
|
|
Datum values[MaxHeapAttributeNumber];
|
|
int natt;
|
|
|
|
*copy = false;
|
|
|
|
if (!RelationIsLogicallyLogged(relation))
|
|
return NULL;
|
|
|
|
if (replident == REPLICA_IDENTITY_NOTHING)
|
|
return NULL;
|
|
|
|
if (replident == REPLICA_IDENTITY_FULL)
|
|
{
|
|
/*
|
|
* When logging the entire old tuple, it very well could contain
|
|
* toasted columns. If so, force them to be inlined.
|
|
*/
|
|
if (HeapTupleHasExternal(tp))
|
|
{
|
|
*copy = true;
|
|
tp = toast_flatten_tuple(tp, RelationGetDescr(relation));
|
|
}
|
|
return tp;
|
|
}
|
|
|
|
/* if the key hasn't changed and we're only logging the key, we're done */
|
|
if (!key_changed)
|
|
return NULL;
|
|
|
|
/* find the replica identity index */
|
|
replidindex = RelationGetReplicaIndex(relation);
|
|
if (!OidIsValid(replidindex))
|
|
{
|
|
elog(DEBUG4, "could not find configured replica identity for table \"%s\"",
|
|
RelationGetRelationName(relation));
|
|
return NULL;
|
|
}
|
|
|
|
idx_rel = RelationIdGetRelation(replidindex);
|
|
idx_desc = RelationGetDescr(idx_rel);
|
|
|
|
/* deform tuple, so we have fast access to columns */
|
|
heap_deform_tuple(tp, desc, values, nulls);
|
|
|
|
/* set all columns to NULL, regardless of whether they actually are */
|
|
memset(nulls, 1, sizeof(nulls));
|
|
|
|
/*
|
|
* Now set all columns contained in the index to NOT NULL, they cannot
|
|
* currently be NULL.
|
|
*/
|
|
for (natt = 0; natt < idx_desc->natts; natt++)
|
|
{
|
|
int attno = idx_rel->rd_index->indkey.values[natt];
|
|
|
|
if (attno < 0)
|
|
{
|
|
/*
|
|
* The OID column can appear in an index definition, but that's
|
|
* OK, because we always copy the OID if present (see below).
|
|
* Other system columns may not.
|
|
*/
|
|
if (attno == ObjectIdAttributeNumber)
|
|
continue;
|
|
elog(ERROR, "system column in index");
|
|
}
|
|
nulls[attno - 1] = false;
|
|
}
|
|
|
|
key_tuple = heap_form_tuple(desc, values, nulls);
|
|
*copy = true;
|
|
RelationClose(idx_rel);
|
|
|
|
/*
|
|
* Always copy oids if the table has them, even if not included in the
|
|
* index. The space in the logged tuple is used anyway, so there's little
|
|
* point in not including the information.
|
|
*/
|
|
if (relation->rd_rel->relhasoids)
|
|
HeapTupleSetOid(key_tuple, HeapTupleGetOid(tp));
|
|
|
|
/*
|
|
* If the tuple, which by here only contains indexed columns, still has
|
|
* toasted columns, force them to be inlined. This is somewhat unlikely
|
|
* since there's limits on the size of indexed columns, so we don't
|
|
* duplicate toast_flatten_tuple()s functionality in the above loop over
|
|
* the indexed columns, even if it would be more efficient.
|
|
*/
|
|
if (HeapTupleHasExternal(key_tuple))
|
|
{
|
|
HeapTuple oldtup = key_tuple;
|
|
|
|
key_tuple = toast_flatten_tuple(oldtup, RelationGetDescr(relation));
|
|
heap_freetuple(oldtup);
|
|
}
|
|
|
|
return key_tuple;
|
|
}
|
|
|
|
/*
|
|
* Handles CLEANUP_INFO
|
|
*/
|
|
static void
|
|
heap_xlog_cleanup_info(XLogReaderState *record)
|
|
{
|
|
xl_heap_cleanup_info *xlrec = (xl_heap_cleanup_info *) XLogRecGetData(record);
|
|
|
|
if (InHotStandby)
|
|
ResolveRecoveryConflictWithSnapshot(xlrec->latestRemovedXid, xlrec->node);
|
|
|
|
/*
|
|
* Actual operation is a no-op. Record type exists to provide a means for
|
|
* conflict processing to occur before we begin index vacuum actions. see
|
|
* vacuumlazy.c and also comments in btvacuumpage()
|
|
*/
|
|
|
|
/* Backup blocks are not used in cleanup_info records */
|
|
Assert(!XLogRecHasAnyBlockRefs(record));
|
|
}
|
|
|
|
/*
|
|
* Handles HEAP2_CLEAN record type
|
|
*/
|
|
static void
|
|
heap_xlog_clean(XLogReaderState *record)
|
|
{
|
|
XLogRecPtr lsn = record->EndRecPtr;
|
|
xl_heap_clean *xlrec = (xl_heap_clean *) XLogRecGetData(record);
|
|
Buffer buffer;
|
|
Size freespace = 0;
|
|
RelFileNode rnode;
|
|
BlockNumber blkno;
|
|
XLogRedoAction action;
|
|
|
|
XLogRecGetBlockTag(record, 0, &rnode, NULL, &blkno);
|
|
|
|
/*
|
|
* We're about to remove tuples. In Hot Standby mode, ensure that there's
|
|
* no queries running for which the removed tuples are still visible.
|
|
*
|
|
* Not all HEAP2_CLEAN records remove tuples with xids, so we only want to
|
|
* conflict on the records that cause MVCC failures for user queries. If
|
|
* latestRemovedXid is invalid, skip conflict processing.
|
|
*/
|
|
if (InHotStandby && TransactionIdIsValid(xlrec->latestRemovedXid))
|
|
ResolveRecoveryConflictWithSnapshot(xlrec->latestRemovedXid, rnode);
|
|
|
|
/*
|
|
* If we have a full-page image, restore it (using a cleanup lock) and
|
|
* we're done.
|
|
*/
|
|
action = XLogReadBufferForRedoExtended(record, 0, RBM_NORMAL, true,
|
|
&buffer);
|
|
if (action == BLK_NEEDS_REDO)
|
|
{
|
|
Page page = (Page) BufferGetPage(buffer);
|
|
OffsetNumber *end;
|
|
OffsetNumber *redirected;
|
|
OffsetNumber *nowdead;
|
|
OffsetNumber *nowunused;
|
|
int nredirected;
|
|
int ndead;
|
|
int nunused;
|
|
Size datalen;
|
|
|
|
redirected = (OffsetNumber *) XLogRecGetBlockData(record, 0, &datalen);
|
|
|
|
nredirected = xlrec->nredirected;
|
|
ndead = xlrec->ndead;
|
|
end = (OffsetNumber *) ((char *) redirected + datalen);
|
|
nowdead = redirected + (nredirected * 2);
|
|
nowunused = nowdead + ndead;
|
|
nunused = (end - nowunused);
|
|
Assert(nunused >= 0);
|
|
|
|
/* Update all item pointers per the record, and repair fragmentation */
|
|
heap_page_prune_execute(buffer,
|
|
redirected, nredirected,
|
|
nowdead, ndead,
|
|
nowunused, nunused);
|
|
|
|
freespace = PageGetHeapFreeSpace(page); /* needed to update FSM below */
|
|
|
|
/*
|
|
* Note: we don't worry about updating the page's prunability hints.
|
|
* At worst this will cause an extra prune cycle to occur soon.
|
|
*/
|
|
|
|
PageSetLSN(page, lsn);
|
|
MarkBufferDirty(buffer);
|
|
}
|
|
if (BufferIsValid(buffer))
|
|
UnlockReleaseBuffer(buffer);
|
|
|
|
/*
|
|
* Update the FSM as well.
|
|
*
|
|
* XXX: Don't do this if the page was restored from full page image. We
|
|
* don't bother to update the FSM in that case, it doesn't need to be
|
|
* totally accurate anyway.
|
|
*/
|
|
if (action == BLK_NEEDS_REDO)
|
|
XLogRecordPageWithFreeSpace(rnode, blkno, freespace);
|
|
}
|
|
|
|
/*
|
|
* Replay XLOG_HEAP2_VISIBLE record.
|
|
*
|
|
* The critical integrity requirement here is that we must never end up with
|
|
* a situation where the visibility map bit is set, and the page-level
|
|
* PD_ALL_VISIBLE bit is clear. If that were to occur, then a subsequent
|
|
* page modification would fail to clear the visibility map bit.
|
|
*/
|
|
static void
|
|
heap_xlog_visible(XLogReaderState *record)
|
|
{
|
|
XLogRecPtr lsn = record->EndRecPtr;
|
|
xl_heap_visible *xlrec = (xl_heap_visible *) XLogRecGetData(record);
|
|
Buffer vmbuffer = InvalidBuffer;
|
|
Buffer buffer;
|
|
Page page;
|
|
RelFileNode rnode;
|
|
BlockNumber blkno;
|
|
XLogRedoAction action;
|
|
|
|
XLogRecGetBlockTag(record, 1, &rnode, NULL, &blkno);
|
|
|
|
/*
|
|
* If there are any Hot Standby transactions running that have an xmin
|
|
* horizon old enough that this page isn't all-visible for them, they
|
|
* might incorrectly decide that an index-only scan can skip a heap fetch.
|
|
*
|
|
* NB: It might be better to throw some kind of "soft" conflict here that
|
|
* forces any index-only scan that is in flight to perform heap fetches,
|
|
* rather than killing the transaction outright.
|
|
*/
|
|
if (InHotStandby)
|
|
ResolveRecoveryConflictWithSnapshot(xlrec->cutoff_xid, rnode);
|
|
|
|
/*
|
|
* Read the heap page, if it still exists. If the heap file has dropped or
|
|
* truncated later in recovery, we don't need to update the page, but we'd
|
|
* better still update the visibility map.
|
|
*/
|
|
action = XLogReadBufferForRedo(record, 1, &buffer);
|
|
if (action == BLK_NEEDS_REDO)
|
|
{
|
|
/*
|
|
* We don't bump the LSN of the heap page when setting the visibility
|
|
* map bit (unless checksums or wal_hint_bits is enabled, in which
|
|
* case we must), because that would generate an unworkable volume of
|
|
* full-page writes. This exposes us to torn page hazards, but since
|
|
* we're not inspecting the existing page contents in any way, we
|
|
* don't care.
|
|
*
|
|
* However, all operations that clear the visibility map bit *do* bump
|
|
* the LSN, and those operations will only be replayed if the XLOG LSN
|
|
* follows the page LSN. Thus, if the page LSN has advanced past our
|
|
* XLOG record's LSN, we mustn't mark the page all-visible, because
|
|
* the subsequent update won't be replayed to clear the flag.
|
|
*/
|
|
page = BufferGetPage(buffer);
|
|
|
|
PageSetAllVisible(page);
|
|
|
|
MarkBufferDirty(buffer);
|
|
}
|
|
else if (action == BLK_RESTORED)
|
|
{
|
|
/*
|
|
* If heap block was backed up, we already restored it and there's
|
|
* nothing more to do. (This can only happen with checksums or
|
|
* wal_log_hints enabled.)
|
|
*/
|
|
}
|
|
if (BufferIsValid(buffer))
|
|
UnlockReleaseBuffer(buffer);
|
|
|
|
/*
|
|
* Even if we skipped the heap page update due to the LSN interlock, it's
|
|
* still safe to update the visibility map. Any WAL record that clears
|
|
* the visibility map bit does so before checking the page LSN, so any
|
|
* bits that need to be cleared will still be cleared.
|
|
*/
|
|
if (XLogReadBufferForRedoExtended(record, 0, RBM_ZERO_ON_ERROR, false,
|
|
&vmbuffer) == BLK_NEEDS_REDO)
|
|
{
|
|
Page vmpage = BufferGetPage(vmbuffer);
|
|
Relation reln;
|
|
|
|
/* initialize the page if it was read as zeros */
|
|
if (PageIsNew(vmpage))
|
|
PageInit(vmpage, BLCKSZ, 0);
|
|
|
|
/*
|
|
* XLogReadBufferForRedoExtended locked the buffer. But
|
|
* visibilitymap_set will handle locking itself.
|
|
*/
|
|
LockBuffer(vmbuffer, BUFFER_LOCK_UNLOCK);
|
|
|
|
reln = CreateFakeRelcacheEntry(rnode);
|
|
visibilitymap_pin(reln, blkno, &vmbuffer);
|
|
|
|
/*
|
|
* Don't set the bit if replay has already passed this point.
|
|
*
|
|
* It might be safe to do this unconditionally; if replay has passed
|
|
* this point, we'll replay at least as far this time as we did
|
|
* before, and if this bit needs to be cleared, the record responsible
|
|
* for doing so should be again replayed, and clear it. For right
|
|
* now, out of an abundance of conservatism, we use the same test here
|
|
* we did for the heap page. If this results in a dropped bit, no
|
|
* real harm is done; and the next VACUUM will fix it.
|
|
*/
|
|
if (lsn > PageGetLSN(vmpage))
|
|
visibilitymap_set(reln, blkno, InvalidBuffer, lsn, vmbuffer,
|
|
xlrec->cutoff_xid, xlrec->flags);
|
|
|
|
ReleaseBuffer(vmbuffer);
|
|
FreeFakeRelcacheEntry(reln);
|
|
}
|
|
else if (BufferIsValid(vmbuffer))
|
|
UnlockReleaseBuffer(vmbuffer);
|
|
}
|
|
|
|
/*
|
|
* Replay XLOG_HEAP2_FREEZE_PAGE records
|
|
*/
|
|
static void
|
|
heap_xlog_freeze_page(XLogReaderState *record)
|
|
{
|
|
XLogRecPtr lsn = record->EndRecPtr;
|
|
xl_heap_freeze_page *xlrec = (xl_heap_freeze_page *) XLogRecGetData(record);
|
|
TransactionId cutoff_xid = xlrec->cutoff_xid;
|
|
Buffer buffer;
|
|
int ntup;
|
|
|
|
/*
|
|
* In Hot Standby mode, ensure that there's no queries running which still
|
|
* consider the frozen xids as running.
|
|
*/
|
|
if (InHotStandby)
|
|
{
|
|
RelFileNode rnode;
|
|
TransactionId latestRemovedXid = cutoff_xid;
|
|
|
|
TransactionIdRetreat(latestRemovedXid);
|
|
|
|
XLogRecGetBlockTag(record, 0, &rnode, NULL, NULL);
|
|
ResolveRecoveryConflictWithSnapshot(latestRemovedXid, rnode);
|
|
}
|
|
|
|
if (XLogReadBufferForRedo(record, 0, &buffer) == BLK_NEEDS_REDO)
|
|
{
|
|
Page page = BufferGetPage(buffer);
|
|
xl_heap_freeze_tuple *tuples;
|
|
|
|
tuples = (xl_heap_freeze_tuple *) XLogRecGetBlockData(record, 0, NULL);
|
|
|
|
/* now execute freeze plan for each frozen tuple */
|
|
for (ntup = 0; ntup < xlrec->ntuples; ntup++)
|
|
{
|
|
xl_heap_freeze_tuple *xlrec_tp;
|
|
ItemId lp;
|
|
HeapTupleHeader tuple;
|
|
|
|
xlrec_tp = &tuples[ntup];
|
|
lp = PageGetItemId(page, xlrec_tp->offset); /* offsets are one-based */
|
|
tuple = (HeapTupleHeader) PageGetItem(page, lp);
|
|
|
|
heap_execute_freeze_tuple(tuple, xlrec_tp);
|
|
}
|
|
|
|
PageSetLSN(page, lsn);
|
|
MarkBufferDirty(buffer);
|
|
}
|
|
if (BufferIsValid(buffer))
|
|
UnlockReleaseBuffer(buffer);
|
|
}
|
|
|
|
/*
|
|
* Given an "infobits" field from an XLog record, set the correct bits in the
|
|
* given infomask and infomask2 for the tuple touched by the record.
|
|
*
|
|
* (This is the reverse of compute_infobits).
|
|
*/
|
|
static void
|
|
fix_infomask_from_infobits(uint8 infobits, uint16 *infomask, uint16 *infomask2)
|
|
{
|
|
*infomask &= ~(HEAP_XMAX_IS_MULTI | HEAP_XMAX_LOCK_ONLY |
|
|
HEAP_XMAX_KEYSHR_LOCK | HEAP_XMAX_EXCL_LOCK);
|
|
*infomask2 &= ~HEAP_KEYS_UPDATED;
|
|
|
|
if (infobits & XLHL_XMAX_IS_MULTI)
|
|
*infomask |= HEAP_XMAX_IS_MULTI;
|
|
if (infobits & XLHL_XMAX_LOCK_ONLY)
|
|
*infomask |= HEAP_XMAX_LOCK_ONLY;
|
|
if (infobits & XLHL_XMAX_EXCL_LOCK)
|
|
*infomask |= HEAP_XMAX_EXCL_LOCK;
|
|
/* note HEAP_XMAX_SHR_LOCK isn't considered here */
|
|
if (infobits & XLHL_XMAX_KEYSHR_LOCK)
|
|
*infomask |= HEAP_XMAX_KEYSHR_LOCK;
|
|
|
|
if (infobits & XLHL_KEYS_UPDATED)
|
|
*infomask2 |= HEAP_KEYS_UPDATED;
|
|
}
|
|
|
|
static void
|
|
heap_xlog_delete(XLogReaderState *record)
|
|
{
|
|
XLogRecPtr lsn = record->EndRecPtr;
|
|
xl_heap_delete *xlrec = (xl_heap_delete *) XLogRecGetData(record);
|
|
Buffer buffer;
|
|
Page page;
|
|
ItemId lp = NULL;
|
|
HeapTupleHeader htup;
|
|
BlockNumber blkno;
|
|
RelFileNode target_node;
|
|
ItemPointerData target_tid;
|
|
|
|
XLogRecGetBlockTag(record, 0, &target_node, NULL, &blkno);
|
|
ItemPointerSetBlockNumber(&target_tid, blkno);
|
|
ItemPointerSetOffsetNumber(&target_tid, xlrec->offnum);
|
|
|
|
/*
|
|
* The visibility map may need to be fixed even if the heap page is
|
|
* already up-to-date.
|
|
*/
|
|
if (xlrec->flags & XLH_DELETE_ALL_VISIBLE_CLEARED)
|
|
{
|
|
Relation reln = CreateFakeRelcacheEntry(target_node);
|
|
Buffer vmbuffer = InvalidBuffer;
|
|
|
|
visibilitymap_pin(reln, blkno, &vmbuffer);
|
|
visibilitymap_clear(reln, blkno, vmbuffer, VISIBILITYMAP_VALID_BITS);
|
|
ReleaseBuffer(vmbuffer);
|
|
FreeFakeRelcacheEntry(reln);
|
|
}
|
|
|
|
if (XLogReadBufferForRedo(record, 0, &buffer) == BLK_NEEDS_REDO)
|
|
{
|
|
page = BufferGetPage(buffer);
|
|
|
|
if (PageGetMaxOffsetNumber(page) >= xlrec->offnum)
|
|
lp = PageGetItemId(page, xlrec->offnum);
|
|
|
|
if (PageGetMaxOffsetNumber(page) < xlrec->offnum || !ItemIdIsNormal(lp))
|
|
elog(PANIC, "invalid lp");
|
|
|
|
htup = (HeapTupleHeader) PageGetItem(page, lp);
|
|
|
|
htup->t_infomask &= ~(HEAP_XMAX_BITS | HEAP_MOVED);
|
|
htup->t_infomask2 &= ~HEAP_KEYS_UPDATED;
|
|
HeapTupleHeaderClearHotUpdated(htup);
|
|
fix_infomask_from_infobits(xlrec->infobits_set,
|
|
&htup->t_infomask, &htup->t_infomask2);
|
|
if (!(xlrec->flags & XLH_DELETE_IS_SUPER))
|
|
HeapTupleHeaderSetXmax(htup, xlrec->xmax);
|
|
else
|
|
HeapTupleHeaderSetXmin(htup, InvalidTransactionId);
|
|
HeapTupleHeaderSetCmax(htup, FirstCommandId, false);
|
|
|
|
/* Mark the page as a candidate for pruning */
|
|
PageSetPrunable(page, XLogRecGetXid(record));
|
|
|
|
if (xlrec->flags & XLH_DELETE_ALL_VISIBLE_CLEARED)
|
|
PageClearAllVisible(page);
|
|
|
|
/* Make sure there is no forward chain link in t_ctid */
|
|
htup->t_ctid = target_tid;
|
|
PageSetLSN(page, lsn);
|
|
MarkBufferDirty(buffer);
|
|
}
|
|
if (BufferIsValid(buffer))
|
|
UnlockReleaseBuffer(buffer);
|
|
}
|
|
|
|
static void
|
|
heap_xlog_insert(XLogReaderState *record)
|
|
{
|
|
XLogRecPtr lsn = record->EndRecPtr;
|
|
xl_heap_insert *xlrec = (xl_heap_insert *) XLogRecGetData(record);
|
|
Buffer buffer;
|
|
Page page;
|
|
union
|
|
{
|
|
HeapTupleHeaderData hdr;
|
|
char data[MaxHeapTupleSize];
|
|
} tbuf;
|
|
HeapTupleHeader htup;
|
|
xl_heap_header xlhdr;
|
|
uint32 newlen;
|
|
Size freespace = 0;
|
|
RelFileNode target_node;
|
|
BlockNumber blkno;
|
|
ItemPointerData target_tid;
|
|
XLogRedoAction action;
|
|
|
|
XLogRecGetBlockTag(record, 0, &target_node, NULL, &blkno);
|
|
ItemPointerSetBlockNumber(&target_tid, blkno);
|
|
ItemPointerSetOffsetNumber(&target_tid, xlrec->offnum);
|
|
|
|
/*
|
|
* The visibility map may need to be fixed even if the heap page is
|
|
* already up-to-date.
|
|
*/
|
|
if (xlrec->flags & XLH_INSERT_ALL_VISIBLE_CLEARED)
|
|
{
|
|
Relation reln = CreateFakeRelcacheEntry(target_node);
|
|
Buffer vmbuffer = InvalidBuffer;
|
|
|
|
visibilitymap_pin(reln, blkno, &vmbuffer);
|
|
visibilitymap_clear(reln, blkno, vmbuffer, VISIBILITYMAP_VALID_BITS);
|
|
ReleaseBuffer(vmbuffer);
|
|
FreeFakeRelcacheEntry(reln);
|
|
}
|
|
|
|
/*
|
|
* If we inserted the first and only tuple on the page, re-initialize the
|
|
* page from scratch.
|
|
*/
|
|
if (XLogRecGetInfo(record) & XLOG_HEAP_INIT_PAGE)
|
|
{
|
|
buffer = XLogInitBufferForRedo(record, 0);
|
|
page = BufferGetPage(buffer);
|
|
PageInit(page, BufferGetPageSize(buffer), 0);
|
|
action = BLK_NEEDS_REDO;
|
|
}
|
|
else
|
|
action = XLogReadBufferForRedo(record, 0, &buffer);
|
|
if (action == BLK_NEEDS_REDO)
|
|
{
|
|
Size datalen;
|
|
char *data;
|
|
|
|
page = BufferGetPage(buffer);
|
|
|
|
if (PageGetMaxOffsetNumber(page) + 1 < xlrec->offnum)
|
|
elog(PANIC, "invalid max offset number");
|
|
|
|
data = XLogRecGetBlockData(record, 0, &datalen);
|
|
|
|
newlen = datalen - SizeOfHeapHeader;
|
|
Assert(datalen > SizeOfHeapHeader && newlen <= MaxHeapTupleSize);
|
|
memcpy((char *) &xlhdr, data, SizeOfHeapHeader);
|
|
data += SizeOfHeapHeader;
|
|
|
|
htup = &tbuf.hdr;
|
|
MemSet((char *) htup, 0, SizeofHeapTupleHeader);
|
|
/* PG73FORMAT: get bitmap [+ padding] [+ oid] + data */
|
|
memcpy((char *) htup + SizeofHeapTupleHeader,
|
|
data,
|
|
newlen);
|
|
newlen += SizeofHeapTupleHeader;
|
|
htup->t_infomask2 = xlhdr.t_infomask2;
|
|
htup->t_infomask = xlhdr.t_infomask;
|
|
htup->t_hoff = xlhdr.t_hoff;
|
|
HeapTupleHeaderSetXmin(htup, XLogRecGetXid(record));
|
|
HeapTupleHeaderSetCmin(htup, FirstCommandId);
|
|
htup->t_ctid = target_tid;
|
|
|
|
if (PageAddItem(page, (Item) htup, newlen, xlrec->offnum,
|
|
true, true) == InvalidOffsetNumber)
|
|
elog(PANIC, "failed to add tuple");
|
|
|
|
freespace = PageGetHeapFreeSpace(page); /* needed to update FSM below */
|
|
|
|
PageSetLSN(page, lsn);
|
|
|
|
if (xlrec->flags & XLH_INSERT_ALL_VISIBLE_CLEARED)
|
|
PageClearAllVisible(page);
|
|
|
|
MarkBufferDirty(buffer);
|
|
}
|
|
if (BufferIsValid(buffer))
|
|
UnlockReleaseBuffer(buffer);
|
|
|
|
/*
|
|
* If the page is running low on free space, update the FSM as well.
|
|
* Arbitrarily, our definition of "low" is less than 20%. We can't do much
|
|
* better than that without knowing the fill-factor for the table.
|
|
*
|
|
* XXX: Don't do this if the page was restored from full page image. We
|
|
* don't bother to update the FSM in that case, it doesn't need to be
|
|
* totally accurate anyway.
|
|
*/
|
|
if (action == BLK_NEEDS_REDO && freespace < BLCKSZ / 5)
|
|
XLogRecordPageWithFreeSpace(target_node, blkno, freespace);
|
|
}
|
|
|
|
/*
|
|
* Handles MULTI_INSERT record type.
|
|
*/
|
|
static void
|
|
heap_xlog_multi_insert(XLogReaderState *record)
|
|
{
|
|
XLogRecPtr lsn = record->EndRecPtr;
|
|
xl_heap_multi_insert *xlrec;
|
|
RelFileNode rnode;
|
|
BlockNumber blkno;
|
|
Buffer buffer;
|
|
Page page;
|
|
union
|
|
{
|
|
HeapTupleHeaderData hdr;
|
|
char data[MaxHeapTupleSize];
|
|
} tbuf;
|
|
HeapTupleHeader htup;
|
|
uint32 newlen;
|
|
Size freespace = 0;
|
|
int i;
|
|
bool isinit = (XLogRecGetInfo(record) & XLOG_HEAP_INIT_PAGE) != 0;
|
|
XLogRedoAction action;
|
|
|
|
/*
|
|
* Insertion doesn't overwrite MVCC data, so no conflict processing is
|
|
* required.
|
|
*/
|
|
xlrec = (xl_heap_multi_insert *) XLogRecGetData(record);
|
|
|
|
XLogRecGetBlockTag(record, 0, &rnode, NULL, &blkno);
|
|
|
|
/*
|
|
* The visibility map may need to be fixed even if the heap page is
|
|
* already up-to-date.
|
|
*/
|
|
if (xlrec->flags & XLH_INSERT_ALL_VISIBLE_CLEARED)
|
|
{
|
|
Relation reln = CreateFakeRelcacheEntry(rnode);
|
|
Buffer vmbuffer = InvalidBuffer;
|
|
|
|
visibilitymap_pin(reln, blkno, &vmbuffer);
|
|
visibilitymap_clear(reln, blkno, vmbuffer, VISIBILITYMAP_VALID_BITS);
|
|
ReleaseBuffer(vmbuffer);
|
|
FreeFakeRelcacheEntry(reln);
|
|
}
|
|
|
|
if (isinit)
|
|
{
|
|
buffer = XLogInitBufferForRedo(record, 0);
|
|
page = BufferGetPage(buffer);
|
|
PageInit(page, BufferGetPageSize(buffer), 0);
|
|
action = BLK_NEEDS_REDO;
|
|
}
|
|
else
|
|
action = XLogReadBufferForRedo(record, 0, &buffer);
|
|
if (action == BLK_NEEDS_REDO)
|
|
{
|
|
char *tupdata;
|
|
char *endptr;
|
|
Size len;
|
|
|
|
/* Tuples are stored as block data */
|
|
tupdata = XLogRecGetBlockData(record, 0, &len);
|
|
endptr = tupdata + len;
|
|
|
|
page = (Page) BufferGetPage(buffer);
|
|
|
|
for (i = 0; i < xlrec->ntuples; i++)
|
|
{
|
|
OffsetNumber offnum;
|
|
xl_multi_insert_tuple *xlhdr;
|
|
|
|
/*
|
|
* If we're reinitializing the page, the tuples are stored in
|
|
* order from FirstOffsetNumber. Otherwise there's an array of
|
|
* offsets in the WAL record, and the tuples come after that.
|
|
*/
|
|
if (isinit)
|
|
offnum = FirstOffsetNumber + i;
|
|
else
|
|
offnum = xlrec->offsets[i];
|
|
if (PageGetMaxOffsetNumber(page) + 1 < offnum)
|
|
elog(PANIC, "invalid max offset number");
|
|
|
|
xlhdr = (xl_multi_insert_tuple *) SHORTALIGN(tupdata);
|
|
tupdata = ((char *) xlhdr) + SizeOfMultiInsertTuple;
|
|
|
|
newlen = xlhdr->datalen;
|
|
Assert(newlen <= MaxHeapTupleSize);
|
|
htup = &tbuf.hdr;
|
|
MemSet((char *) htup, 0, SizeofHeapTupleHeader);
|
|
/* PG73FORMAT: get bitmap [+ padding] [+ oid] + data */
|
|
memcpy((char *) htup + SizeofHeapTupleHeader,
|
|
(char *) tupdata,
|
|
newlen);
|
|
tupdata += newlen;
|
|
|
|
newlen += SizeofHeapTupleHeader;
|
|
htup->t_infomask2 = xlhdr->t_infomask2;
|
|
htup->t_infomask = xlhdr->t_infomask;
|
|
htup->t_hoff = xlhdr->t_hoff;
|
|
HeapTupleHeaderSetXmin(htup, XLogRecGetXid(record));
|
|
HeapTupleHeaderSetCmin(htup, FirstCommandId);
|
|
ItemPointerSetBlockNumber(&htup->t_ctid, blkno);
|
|
ItemPointerSetOffsetNumber(&htup->t_ctid, offnum);
|
|
|
|
offnum = PageAddItem(page, (Item) htup, newlen, offnum, true, true);
|
|
if (offnum == InvalidOffsetNumber)
|
|
elog(PANIC, "failed to add tuple");
|
|
}
|
|
if (tupdata != endptr)
|
|
elog(PANIC, "total tuple length mismatch");
|
|
|
|
freespace = PageGetHeapFreeSpace(page); /* needed to update FSM below */
|
|
|
|
PageSetLSN(page, lsn);
|
|
|
|
if (xlrec->flags & XLH_INSERT_ALL_VISIBLE_CLEARED)
|
|
PageClearAllVisible(page);
|
|
|
|
MarkBufferDirty(buffer);
|
|
}
|
|
if (BufferIsValid(buffer))
|
|
UnlockReleaseBuffer(buffer);
|
|
|
|
/*
|
|
* If the page is running low on free space, update the FSM as well.
|
|
* Arbitrarily, our definition of "low" is less than 20%. We can't do much
|
|
* better than that without knowing the fill-factor for the table.
|
|
*
|
|
* XXX: Don't do this if the page was restored from full page image. We
|
|
* don't bother to update the FSM in that case, it doesn't need to be
|
|
* totally accurate anyway.
|
|
*/
|
|
if (action == BLK_NEEDS_REDO && freespace < BLCKSZ / 5)
|
|
XLogRecordPageWithFreeSpace(rnode, blkno, freespace);
|
|
}
|
|
|
|
/*
|
|
* Handles UPDATE and HOT_UPDATE
|
|
*/
|
|
static void
|
|
heap_xlog_update(XLogReaderState *record, bool hot_update)
|
|
{
|
|
XLogRecPtr lsn = record->EndRecPtr;
|
|
xl_heap_update *xlrec = (xl_heap_update *) XLogRecGetData(record);
|
|
RelFileNode rnode;
|
|
BlockNumber oldblk;
|
|
BlockNumber newblk;
|
|
ItemPointerData newtid;
|
|
Buffer obuffer,
|
|
nbuffer;
|
|
Page page;
|
|
OffsetNumber offnum;
|
|
ItemId lp = NULL;
|
|
HeapTupleData oldtup;
|
|
HeapTupleHeader htup;
|
|
uint16 prefixlen = 0,
|
|
suffixlen = 0;
|
|
char *newp;
|
|
union
|
|
{
|
|
HeapTupleHeaderData hdr;
|
|
char data[MaxHeapTupleSize];
|
|
} tbuf;
|
|
xl_heap_header xlhdr;
|
|
uint32 newlen;
|
|
Size freespace = 0;
|
|
XLogRedoAction oldaction;
|
|
XLogRedoAction newaction;
|
|
|
|
/* initialize to keep the compiler quiet */
|
|
oldtup.t_data = NULL;
|
|
oldtup.t_len = 0;
|
|
|
|
XLogRecGetBlockTag(record, 0, &rnode, NULL, &newblk);
|
|
if (XLogRecGetBlockTag(record, 1, NULL, NULL, &oldblk))
|
|
{
|
|
/* HOT updates are never done across pages */
|
|
Assert(!hot_update);
|
|
}
|
|
else
|
|
oldblk = newblk;
|
|
|
|
ItemPointerSet(&newtid, newblk, xlrec->new_offnum);
|
|
|
|
/*
|
|
* The visibility map may need to be fixed even if the heap page is
|
|
* already up-to-date.
|
|
*/
|
|
if (xlrec->flags & XLH_UPDATE_OLD_ALL_VISIBLE_CLEARED)
|
|
{
|
|
Relation reln = CreateFakeRelcacheEntry(rnode);
|
|
Buffer vmbuffer = InvalidBuffer;
|
|
|
|
visibilitymap_pin(reln, oldblk, &vmbuffer);
|
|
visibilitymap_clear(reln, oldblk, vmbuffer, VISIBILITYMAP_VALID_BITS);
|
|
ReleaseBuffer(vmbuffer);
|
|
FreeFakeRelcacheEntry(reln);
|
|
}
|
|
|
|
/*
|
|
* In normal operation, it is important to lock the two pages in
|
|
* page-number order, to avoid possible deadlocks against other update
|
|
* operations going the other way. However, during WAL replay there can
|
|
* be no other update happening, so we don't need to worry about that. But
|
|
* we *do* need to worry that we don't expose an inconsistent state to Hot
|
|
* Standby queries --- so the original page can't be unlocked before we've
|
|
* added the new tuple to the new page.
|
|
*/
|
|
|
|
/* Deal with old tuple version */
|
|
oldaction = XLogReadBufferForRedo(record, (oldblk == newblk) ? 0 : 1,
|
|
&obuffer);
|
|
if (oldaction == BLK_NEEDS_REDO)
|
|
{
|
|
page = BufferGetPage(obuffer);
|
|
offnum = xlrec->old_offnum;
|
|
if (PageGetMaxOffsetNumber(page) >= offnum)
|
|
lp = PageGetItemId(page, offnum);
|
|
|
|
if (PageGetMaxOffsetNumber(page) < offnum || !ItemIdIsNormal(lp))
|
|
elog(PANIC, "invalid lp");
|
|
|
|
htup = (HeapTupleHeader) PageGetItem(page, lp);
|
|
|
|
oldtup.t_data = htup;
|
|
oldtup.t_len = ItemIdGetLength(lp);
|
|
|
|
htup->t_infomask &= ~(HEAP_XMAX_BITS | HEAP_MOVED);
|
|
htup->t_infomask2 &= ~HEAP_KEYS_UPDATED;
|
|
if (hot_update)
|
|
HeapTupleHeaderSetHotUpdated(htup);
|
|
else
|
|
HeapTupleHeaderClearHotUpdated(htup);
|
|
fix_infomask_from_infobits(xlrec->old_infobits_set, &htup->t_infomask,
|
|
&htup->t_infomask2);
|
|
HeapTupleHeaderSetXmax(htup, xlrec->old_xmax);
|
|
HeapTupleHeaderSetCmax(htup, FirstCommandId, false);
|
|
/* Set forward chain link in t_ctid */
|
|
htup->t_ctid = newtid;
|
|
|
|
/* Mark the page as a candidate for pruning */
|
|
PageSetPrunable(page, XLogRecGetXid(record));
|
|
|
|
if (xlrec->flags & XLH_UPDATE_OLD_ALL_VISIBLE_CLEARED)
|
|
PageClearAllVisible(page);
|
|
|
|
PageSetLSN(page, lsn);
|
|
MarkBufferDirty(obuffer);
|
|
}
|
|
|
|
/*
|
|
* Read the page the new tuple goes into, if different from old.
|
|
*/
|
|
if (oldblk == newblk)
|
|
{
|
|
nbuffer = obuffer;
|
|
newaction = oldaction;
|
|
}
|
|
else if (XLogRecGetInfo(record) & XLOG_HEAP_INIT_PAGE)
|
|
{
|
|
nbuffer = XLogInitBufferForRedo(record, 0);
|
|
page = (Page) BufferGetPage(nbuffer);
|
|
PageInit(page, BufferGetPageSize(nbuffer), 0);
|
|
newaction = BLK_NEEDS_REDO;
|
|
}
|
|
else
|
|
newaction = XLogReadBufferForRedo(record, 0, &nbuffer);
|
|
|
|
/*
|
|
* The visibility map may need to be fixed even if the heap page is
|
|
* already up-to-date.
|
|
*/
|
|
if (xlrec->flags & XLH_UPDATE_NEW_ALL_VISIBLE_CLEARED)
|
|
{
|
|
Relation reln = CreateFakeRelcacheEntry(rnode);
|
|
Buffer vmbuffer = InvalidBuffer;
|
|
|
|
visibilitymap_pin(reln, newblk, &vmbuffer);
|
|
visibilitymap_clear(reln, newblk, vmbuffer, VISIBILITYMAP_VALID_BITS);
|
|
ReleaseBuffer(vmbuffer);
|
|
FreeFakeRelcacheEntry(reln);
|
|
}
|
|
|
|
/* Deal with new tuple */
|
|
if (newaction == BLK_NEEDS_REDO)
|
|
{
|
|
char *recdata;
|
|
char *recdata_end;
|
|
Size datalen;
|
|
Size tuplen;
|
|
|
|
recdata = XLogRecGetBlockData(record, 0, &datalen);
|
|
recdata_end = recdata + datalen;
|
|
|
|
page = BufferGetPage(nbuffer);
|
|
|
|
offnum = xlrec->new_offnum;
|
|
if (PageGetMaxOffsetNumber(page) + 1 < offnum)
|
|
elog(PANIC, "invalid max offset number");
|
|
|
|
if (xlrec->flags & XLH_UPDATE_PREFIX_FROM_OLD)
|
|
{
|
|
Assert(newblk == oldblk);
|
|
memcpy(&prefixlen, recdata, sizeof(uint16));
|
|
recdata += sizeof(uint16);
|
|
}
|
|
if (xlrec->flags & XLH_UPDATE_SUFFIX_FROM_OLD)
|
|
{
|
|
Assert(newblk == oldblk);
|
|
memcpy(&suffixlen, recdata, sizeof(uint16));
|
|
recdata += sizeof(uint16);
|
|
}
|
|
|
|
memcpy((char *) &xlhdr, recdata, SizeOfHeapHeader);
|
|
recdata += SizeOfHeapHeader;
|
|
|
|
tuplen = recdata_end - recdata;
|
|
Assert(tuplen <= MaxHeapTupleSize);
|
|
|
|
htup = &tbuf.hdr;
|
|
MemSet((char *) htup, 0, SizeofHeapTupleHeader);
|
|
|
|
/*
|
|
* Reconstruct the new tuple using the prefix and/or suffix from the
|
|
* old tuple, and the data stored in the WAL record.
|
|
*/
|
|
newp = (char *) htup + SizeofHeapTupleHeader;
|
|
if (prefixlen > 0)
|
|
{
|
|
int len;
|
|
|
|
/* copy bitmap [+ padding] [+ oid] from WAL record */
|
|
len = xlhdr.t_hoff - SizeofHeapTupleHeader;
|
|
memcpy(newp, recdata, len);
|
|
recdata += len;
|
|
newp += len;
|
|
|
|
/* copy prefix from old tuple */
|
|
memcpy(newp, (char *) oldtup.t_data + oldtup.t_data->t_hoff, prefixlen);
|
|
newp += prefixlen;
|
|
|
|
/* copy new tuple data from WAL record */
|
|
len = tuplen - (xlhdr.t_hoff - SizeofHeapTupleHeader);
|
|
memcpy(newp, recdata, len);
|
|
recdata += len;
|
|
newp += len;
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* copy bitmap [+ padding] [+ oid] + data from record, all in one
|
|
* go
|
|
*/
|
|
memcpy(newp, recdata, tuplen);
|
|
recdata += tuplen;
|
|
newp += tuplen;
|
|
}
|
|
Assert(recdata == recdata_end);
|
|
|
|
/* copy suffix from old tuple */
|
|
if (suffixlen > 0)
|
|
memcpy(newp, (char *) oldtup.t_data + oldtup.t_len - suffixlen, suffixlen);
|
|
|
|
newlen = SizeofHeapTupleHeader + tuplen + prefixlen + suffixlen;
|
|
htup->t_infomask2 = xlhdr.t_infomask2;
|
|
htup->t_infomask = xlhdr.t_infomask;
|
|
htup->t_hoff = xlhdr.t_hoff;
|
|
|
|
HeapTupleHeaderSetXmin(htup, XLogRecGetXid(record));
|
|
HeapTupleHeaderSetCmin(htup, FirstCommandId);
|
|
HeapTupleHeaderSetXmax(htup, xlrec->new_xmax);
|
|
/* Make sure there is no forward chain link in t_ctid */
|
|
htup->t_ctid = newtid;
|
|
|
|
offnum = PageAddItem(page, (Item) htup, newlen, offnum, true, true);
|
|
if (offnum == InvalidOffsetNumber)
|
|
elog(PANIC, "failed to add tuple");
|
|
|
|
if (xlrec->flags & XLH_UPDATE_NEW_ALL_VISIBLE_CLEARED)
|
|
PageClearAllVisible(page);
|
|
|
|
freespace = PageGetHeapFreeSpace(page); /* needed to update FSM below */
|
|
|
|
PageSetLSN(page, lsn);
|
|
MarkBufferDirty(nbuffer);
|
|
}
|
|
|
|
if (BufferIsValid(nbuffer) && nbuffer != obuffer)
|
|
UnlockReleaseBuffer(nbuffer);
|
|
if (BufferIsValid(obuffer))
|
|
UnlockReleaseBuffer(obuffer);
|
|
|
|
/*
|
|
* If the new page is running low on free space, update the FSM as well.
|
|
* Arbitrarily, our definition of "low" is less than 20%. We can't do much
|
|
* better than that without knowing the fill-factor for the table.
|
|
*
|
|
* However, don't update the FSM on HOT updates, because after crash
|
|
* recovery, either the old or the new tuple will certainly be dead and
|
|
* prunable. After pruning, the page will have roughly as much free space
|
|
* as it did before the update, assuming the new tuple is about the same
|
|
* size as the old one.
|
|
*
|
|
* XXX: Don't do this if the page was restored from full page image. We
|
|
* don't bother to update the FSM in that case, it doesn't need to be
|
|
* totally accurate anyway.
|
|
*/
|
|
if (newaction == BLK_NEEDS_REDO && !hot_update && freespace < BLCKSZ / 5)
|
|
XLogRecordPageWithFreeSpace(rnode, newblk, freespace);
|
|
}
|
|
|
|
static void
|
|
heap_xlog_confirm(XLogReaderState *record)
|
|
{
|
|
XLogRecPtr lsn = record->EndRecPtr;
|
|
xl_heap_confirm *xlrec = (xl_heap_confirm *) XLogRecGetData(record);
|
|
Buffer buffer;
|
|
Page page;
|
|
OffsetNumber offnum;
|
|
ItemId lp = NULL;
|
|
HeapTupleHeader htup;
|
|
|
|
if (XLogReadBufferForRedo(record, 0, &buffer) == BLK_NEEDS_REDO)
|
|
{
|
|
page = BufferGetPage(buffer);
|
|
|
|
offnum = xlrec->offnum;
|
|
if (PageGetMaxOffsetNumber(page) >= offnum)
|
|
lp = PageGetItemId(page, offnum);
|
|
|
|
if (PageGetMaxOffsetNumber(page) < offnum || !ItemIdIsNormal(lp))
|
|
elog(PANIC, "invalid lp");
|
|
|
|
htup = (HeapTupleHeader) PageGetItem(page, lp);
|
|
|
|
/*
|
|
* Confirm tuple as actually inserted
|
|
*/
|
|
ItemPointerSet(&htup->t_ctid, BufferGetBlockNumber(buffer), offnum);
|
|
|
|
PageSetLSN(page, lsn);
|
|
MarkBufferDirty(buffer);
|
|
}
|
|
if (BufferIsValid(buffer))
|
|
UnlockReleaseBuffer(buffer);
|
|
}
|
|
|
|
static void
|
|
heap_xlog_lock(XLogReaderState *record)
|
|
{
|
|
XLogRecPtr lsn = record->EndRecPtr;
|
|
xl_heap_lock *xlrec = (xl_heap_lock *) XLogRecGetData(record);
|
|
Buffer buffer;
|
|
Page page;
|
|
OffsetNumber offnum;
|
|
ItemId lp = NULL;
|
|
HeapTupleHeader htup;
|
|
|
|
/*
|
|
* The visibility map may need to be fixed even if the heap page is
|
|
* already up-to-date.
|
|
*/
|
|
if (xlrec->flags & XLH_LOCK_ALL_FROZEN_CLEARED)
|
|
{
|
|
RelFileNode rnode;
|
|
Buffer vmbuffer = InvalidBuffer;
|
|
BlockNumber block;
|
|
Relation reln;
|
|
|
|
XLogRecGetBlockTag(record, 0, &rnode, NULL, &block);
|
|
reln = CreateFakeRelcacheEntry(rnode);
|
|
|
|
visibilitymap_pin(reln, block, &vmbuffer);
|
|
visibilitymap_clear(reln, block, vmbuffer, VISIBILITYMAP_ALL_FROZEN);
|
|
|
|
ReleaseBuffer(vmbuffer);
|
|
FreeFakeRelcacheEntry(reln);
|
|
}
|
|
|
|
if (XLogReadBufferForRedo(record, 0, &buffer) == BLK_NEEDS_REDO)
|
|
{
|
|
page = (Page) BufferGetPage(buffer);
|
|
|
|
offnum = xlrec->offnum;
|
|
if (PageGetMaxOffsetNumber(page) >= offnum)
|
|
lp = PageGetItemId(page, offnum);
|
|
|
|
if (PageGetMaxOffsetNumber(page) < offnum || !ItemIdIsNormal(lp))
|
|
elog(PANIC, "invalid lp");
|
|
|
|
htup = (HeapTupleHeader) PageGetItem(page, lp);
|
|
|
|
htup->t_infomask &= ~(HEAP_XMAX_BITS | HEAP_MOVED);
|
|
htup->t_infomask2 &= ~HEAP_KEYS_UPDATED;
|
|
fix_infomask_from_infobits(xlrec->infobits_set, &htup->t_infomask,
|
|
&htup->t_infomask2);
|
|
|
|
/*
|
|
* Clear relevant update flags, but only if the modified infomask says
|
|
* there's no update.
|
|
*/
|
|
if (HEAP_XMAX_IS_LOCKED_ONLY(htup->t_infomask))
|
|
{
|
|
HeapTupleHeaderClearHotUpdated(htup);
|
|
/* Make sure there is no forward chain link in t_ctid */
|
|
ItemPointerSet(&htup->t_ctid,
|
|
BufferGetBlockNumber(buffer),
|
|
offnum);
|
|
}
|
|
HeapTupleHeaderSetXmax(htup, xlrec->locking_xid);
|
|
HeapTupleHeaderSetCmax(htup, FirstCommandId, false);
|
|
PageSetLSN(page, lsn);
|
|
MarkBufferDirty(buffer);
|
|
}
|
|
if (BufferIsValid(buffer))
|
|
UnlockReleaseBuffer(buffer);
|
|
}
|
|
|
|
static void
|
|
heap_xlog_lock_updated(XLogReaderState *record)
|
|
{
|
|
XLogRecPtr lsn = record->EndRecPtr;
|
|
xl_heap_lock_updated *xlrec;
|
|
Buffer buffer;
|
|
Page page;
|
|
OffsetNumber offnum;
|
|
ItemId lp = NULL;
|
|
HeapTupleHeader htup;
|
|
|
|
xlrec = (xl_heap_lock_updated *) XLogRecGetData(record);
|
|
|
|
/*
|
|
* The visibility map may need to be fixed even if the heap page is
|
|
* already up-to-date.
|
|
*/
|
|
if (xlrec->flags & XLH_LOCK_ALL_FROZEN_CLEARED)
|
|
{
|
|
RelFileNode rnode;
|
|
Buffer vmbuffer = InvalidBuffer;
|
|
BlockNumber block;
|
|
Relation reln;
|
|
|
|
XLogRecGetBlockTag(record, 0, &rnode, NULL, &block);
|
|
reln = CreateFakeRelcacheEntry(rnode);
|
|
|
|
visibilitymap_pin(reln, block, &vmbuffer);
|
|
visibilitymap_clear(reln, block, vmbuffer, VISIBILITYMAP_ALL_FROZEN);
|
|
|
|
ReleaseBuffer(vmbuffer);
|
|
FreeFakeRelcacheEntry(reln);
|
|
}
|
|
|
|
if (XLogReadBufferForRedo(record, 0, &buffer) == BLK_NEEDS_REDO)
|
|
{
|
|
page = BufferGetPage(buffer);
|
|
|
|
offnum = xlrec->offnum;
|
|
if (PageGetMaxOffsetNumber(page) >= offnum)
|
|
lp = PageGetItemId(page, offnum);
|
|
|
|
if (PageGetMaxOffsetNumber(page) < offnum || !ItemIdIsNormal(lp))
|
|
elog(PANIC, "invalid lp");
|
|
|
|
htup = (HeapTupleHeader) PageGetItem(page, lp);
|
|
|
|
htup->t_infomask &= ~(HEAP_XMAX_BITS | HEAP_MOVED);
|
|
htup->t_infomask2 &= ~HEAP_KEYS_UPDATED;
|
|
fix_infomask_from_infobits(xlrec->infobits_set, &htup->t_infomask,
|
|
&htup->t_infomask2);
|
|
HeapTupleHeaderSetXmax(htup, xlrec->xmax);
|
|
|
|
PageSetLSN(page, lsn);
|
|
MarkBufferDirty(buffer);
|
|
}
|
|
if (BufferIsValid(buffer))
|
|
UnlockReleaseBuffer(buffer);
|
|
}
|
|
|
|
static void
|
|
heap_xlog_inplace(XLogReaderState *record)
|
|
{
|
|
XLogRecPtr lsn = record->EndRecPtr;
|
|
xl_heap_inplace *xlrec = (xl_heap_inplace *) XLogRecGetData(record);
|
|
Buffer buffer;
|
|
Page page;
|
|
OffsetNumber offnum;
|
|
ItemId lp = NULL;
|
|
HeapTupleHeader htup;
|
|
uint32 oldlen;
|
|
Size newlen;
|
|
|
|
if (XLogReadBufferForRedo(record, 0, &buffer) == BLK_NEEDS_REDO)
|
|
{
|
|
char *newtup = XLogRecGetBlockData(record, 0, &newlen);
|
|
|
|
page = BufferGetPage(buffer);
|
|
|
|
offnum = xlrec->offnum;
|
|
if (PageGetMaxOffsetNumber(page) >= offnum)
|
|
lp = PageGetItemId(page, offnum);
|
|
|
|
if (PageGetMaxOffsetNumber(page) < offnum || !ItemIdIsNormal(lp))
|
|
elog(PANIC, "invalid lp");
|
|
|
|
htup = (HeapTupleHeader) PageGetItem(page, lp);
|
|
|
|
oldlen = ItemIdGetLength(lp) - htup->t_hoff;
|
|
if (oldlen != newlen)
|
|
elog(PANIC, "wrong tuple length");
|
|
|
|
memcpy((char *) htup + htup->t_hoff, newtup, newlen);
|
|
|
|
PageSetLSN(page, lsn);
|
|
MarkBufferDirty(buffer);
|
|
}
|
|
if (BufferIsValid(buffer))
|
|
UnlockReleaseBuffer(buffer);
|
|
}
|
|
|
|
void
|
|
heap_redo(XLogReaderState *record)
|
|
{
|
|
uint8 info = XLogRecGetInfo(record) & ~XLR_INFO_MASK;
|
|
|
|
/*
|
|
* These operations don't overwrite MVCC data so no conflict processing is
|
|
* required. The ones in heap2 rmgr do.
|
|
*/
|
|
|
|
switch (info & XLOG_HEAP_OPMASK)
|
|
{
|
|
case XLOG_HEAP_INSERT:
|
|
heap_xlog_insert(record);
|
|
break;
|
|
case XLOG_HEAP_DELETE:
|
|
heap_xlog_delete(record);
|
|
break;
|
|
case XLOG_HEAP_UPDATE:
|
|
heap_xlog_update(record, false);
|
|
break;
|
|
case XLOG_HEAP_HOT_UPDATE:
|
|
heap_xlog_update(record, true);
|
|
break;
|
|
case XLOG_HEAP_CONFIRM:
|
|
heap_xlog_confirm(record);
|
|
break;
|
|
case XLOG_HEAP_LOCK:
|
|
heap_xlog_lock(record);
|
|
break;
|
|
case XLOG_HEAP_INPLACE:
|
|
heap_xlog_inplace(record);
|
|
break;
|
|
default:
|
|
elog(PANIC, "heap_redo: unknown op code %u", info);
|
|
}
|
|
}
|
|
|
|
void
|
|
heap2_redo(XLogReaderState *record)
|
|
{
|
|
uint8 info = XLogRecGetInfo(record) & ~XLR_INFO_MASK;
|
|
|
|
switch (info & XLOG_HEAP_OPMASK)
|
|
{
|
|
case XLOG_HEAP2_CLEAN:
|
|
heap_xlog_clean(record);
|
|
break;
|
|
case XLOG_HEAP2_FREEZE_PAGE:
|
|
heap_xlog_freeze_page(record);
|
|
break;
|
|
case XLOG_HEAP2_CLEANUP_INFO:
|
|
heap_xlog_cleanup_info(record);
|
|
break;
|
|
case XLOG_HEAP2_VISIBLE:
|
|
heap_xlog_visible(record);
|
|
break;
|
|
case XLOG_HEAP2_MULTI_INSERT:
|
|
heap_xlog_multi_insert(record);
|
|
break;
|
|
case XLOG_HEAP2_LOCK_UPDATED:
|
|
heap_xlog_lock_updated(record);
|
|
break;
|
|
case XLOG_HEAP2_NEW_CID:
|
|
|
|
/*
|
|
* Nothing to do on a real replay, only used during logical
|
|
* decoding.
|
|
*/
|
|
break;
|
|
case XLOG_HEAP2_REWRITE:
|
|
heap_xlog_logical_rewrite(record);
|
|
break;
|
|
default:
|
|
elog(PANIC, "heap2_redo: unknown op code %u", info);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* heap_sync - sync a heap, for use when no WAL has been written
|
|
*
|
|
* This forces the heap contents (including TOAST heap if any) down to disk.
|
|
* If we skipped using WAL, and WAL is otherwise needed, we must force the
|
|
* relation down to disk before it's safe to commit the transaction. This
|
|
* requires writing out any dirty buffers and then doing a forced fsync.
|
|
*
|
|
* Indexes are not touched. (Currently, index operations associated with
|
|
* the commands that use this are WAL-logged and so do not need fsync.
|
|
* That behavior might change someday, but in any case it's likely that
|
|
* any fsync decisions required would be per-index and hence not appropriate
|
|
* to be done here.)
|
|
*/
|
|
void
|
|
heap_sync(Relation rel)
|
|
{
|
|
/* non-WAL-logged tables never need fsync */
|
|
if (!RelationNeedsWAL(rel))
|
|
return;
|
|
|
|
/* main heap */
|
|
FlushRelationBuffers(rel);
|
|
/* FlushRelationBuffers will have opened rd_smgr */
|
|
smgrimmedsync(rel->rd_smgr, MAIN_FORKNUM);
|
|
|
|
/* FSM is not critical, don't bother syncing it */
|
|
|
|
/* toast heap, if any */
|
|
if (OidIsValid(rel->rd_rel->reltoastrelid))
|
|
{
|
|
Relation toastrel;
|
|
|
|
toastrel = heap_open(rel->rd_rel->reltoastrelid, AccessShareLock);
|
|
FlushRelationBuffers(toastrel);
|
|
smgrimmedsync(toastrel->rd_smgr, MAIN_FORKNUM);
|
|
heap_close(toastrel, AccessShareLock);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Mask a heap page before performing consistency checks on it.
|
|
*/
|
|
void
|
|
heap_mask(char *pagedata, BlockNumber blkno)
|
|
{
|
|
Page page = (Page) pagedata;
|
|
OffsetNumber off;
|
|
|
|
mask_page_lsn_and_checksum(page);
|
|
|
|
mask_page_hint_bits(page);
|
|
mask_unused_space(page);
|
|
|
|
for (off = 1; off <= PageGetMaxOffsetNumber(page); off++)
|
|
{
|
|
ItemId iid = PageGetItemId(page, off);
|
|
char *page_item;
|
|
|
|
page_item = (char *) (page + ItemIdGetOffset(iid));
|
|
|
|
if (ItemIdIsNormal(iid))
|
|
{
|
|
HeapTupleHeader page_htup = (HeapTupleHeader) page_item;
|
|
|
|
/*
|
|
* If xmin of a tuple is not yet frozen, we should ignore
|
|
* differences in hint bits, since they can be set without
|
|
* emitting WAL.
|
|
*/
|
|
if (!HeapTupleHeaderXminFrozen(page_htup))
|
|
page_htup->t_infomask &= ~HEAP_XACT_MASK;
|
|
else
|
|
{
|
|
/* Still we need to mask xmax hint bits. */
|
|
page_htup->t_infomask &= ~HEAP_XMAX_INVALID;
|
|
page_htup->t_infomask &= ~HEAP_XMAX_COMMITTED;
|
|
}
|
|
|
|
/*
|
|
* During replay, we set Command Id to FirstCommandId. Hence, mask
|
|
* it. See heap_xlog_insert() for details.
|
|
*/
|
|
page_htup->t_choice.t_heap.t_field3.t_cid = MASK_MARKER;
|
|
|
|
/*
|
|
* For a speculative tuple, heap_insert() does not set ctid in the
|
|
* caller-passed heap tuple itself, leaving the ctid field to
|
|
* contain a speculative token value - a per-backend monotonically
|
|
* increasing identifier. Besides, it does not WAL-log ctid under
|
|
* any circumstances.
|
|
*
|
|
* During redo, heap_xlog_insert() sets t_ctid to current block
|
|
* number and self offset number. It doesn't care about any
|
|
* speculative insertions in master. Hence, we set t_ctid to
|
|
* current block number and self offset number to ignore any
|
|
* inconsistency.
|
|
*/
|
|
if (HeapTupleHeaderIsSpeculative(page_htup))
|
|
ItemPointerSet(&page_htup->t_ctid, blkno, off);
|
|
}
|
|
|
|
/*
|
|
* Ignore any padding bytes after the tuple, when the length of the
|
|
* item is not MAXALIGNed.
|
|
*/
|
|
if (ItemIdHasStorage(iid))
|
|
{
|
|
int len = ItemIdGetLength(iid);
|
|
int padlen = MAXALIGN(len) - len;
|
|
|
|
if (padlen > 0)
|
|
memset(page_item + len, MASK_MARKER, padlen);
|
|
}
|
|
}
|
|
}
|