postgresql/src/include/access/gist_private.h

553 lines
19 KiB
C
Raw Normal View History

/*-------------------------------------------------------------------------
*
* gist_private.h
* private declarations for GiST -- declarations related to the
* internal implementation of GiST, not the public API
*
* Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
2010-09-20 22:08:53 +02:00
* src/include/access/gist_private.h
*
*-------------------------------------------------------------------------
*/
#ifndef GIST_PRIVATE_H
#define GIST_PRIVATE_H
#include "access/amapi.h"
#include "access/gist.h"
#include "access/itup.h"
#include "fmgr.h"
#include "lib/pairingheap.h"
#include "storage/bufmgr.h"
#include "storage/buffile.h"
#include "utils/hsearch.h"
#include "access/genam.h"
/*
* Maximum number of "halves" a page can be split into in one operation.
* Typically a split produces 2 halves, but can be more if keys have very
* different lengths, or when inserting multiple keys in one operation (as
* when inserting downlinks to an internal node). There is no theoretical
* limit on this, but in practice if you get more than a handful page halves
* in one split, there's something wrong with the opclass implementation.
* GIST_MAX_SPLIT_PAGES is an arbitrary limit on that, used to size some
* local arrays used during split. Note that there is also a limit on the
* number of buffers that can be held locked at a time, MAX_SIMUL_LWLOCKS,
* so if you raise this higher than that limit, you'll just get a different
* error.
*/
#define GIST_MAX_SPLIT_PAGES 75
/* Buffer lock modes */
#define GIST_SHARE BUFFER_LOCK_SHARE
#define GIST_EXCLUSIVE BUFFER_LOCK_EXCLUSIVE
#define GIST_UNLOCK BUFFER_LOCK_UNLOCK
typedef struct
{
BlockNumber prev;
uint32 freespace;
char tupledata[FLEXIBLE_ARRAY_MEMBER];
} GISTNodeBufferPage;
#define BUFFER_PAGE_DATA_OFFSET MAXALIGN(offsetof(GISTNodeBufferPage, tupledata))
/* Returns free space in node buffer page */
#define PAGE_FREE_SPACE(nbp) (nbp->freespace)
/* Checks if node buffer page is empty */
#define PAGE_IS_EMPTY(nbp) (nbp->freespace == BLCKSZ - BUFFER_PAGE_DATA_OFFSET)
/* Checks if node buffers page don't contain sufficient space for index tuple */
#define PAGE_NO_SPACE(nbp, itup) (PAGE_FREE_SPACE(nbp) < \
MAXALIGN(IndexTupleSize(itup)))
/*
* GISTSTATE: information needed for any GiST index operation
*
* This struct retains call info for the index's opclass-specific support
* functions (per index column), plus the index's tuple descriptor.
*
* scanCxt holds the GISTSTATE itself as well as any data that lives for the
* lifetime of the index operation. We pass this to the support functions
* via fn_mcxt, so that they can store scan-lifespan data in it. The
* functions are invoked in tempCxt, which is typically short-lifespan
* (that is, it's reset after each tuple). However, tempCxt can be the same
* as scanCxt if we're not bothering with per-tuple context resets.
*/
typedef struct GISTSTATE
{
MemoryContext scanCxt; /* context for scan-lifespan data */
MemoryContext tempCxt; /* short-term context for calling functions */
TupleDesc leafTupdesc; /* index's tuple descriptor */
TupleDesc nonLeafTupdesc; /* truncated tuple descriptor for non-leaf
* pages */
TupleDesc fetchTupdesc; /* tuple descriptor for tuples returned in an
* index-only scan */
FmgrInfo consistentFn[INDEX_MAX_KEYS];
FmgrInfo unionFn[INDEX_MAX_KEYS];
FmgrInfo compressFn[INDEX_MAX_KEYS];
FmgrInfo decompressFn[INDEX_MAX_KEYS];
FmgrInfo penaltyFn[INDEX_MAX_KEYS];
FmgrInfo picksplitFn[INDEX_MAX_KEYS];
FmgrInfo equalFn[INDEX_MAX_KEYS];
FmgrInfo distanceFn[INDEX_MAX_KEYS];
FmgrInfo fetchFn[INDEX_MAX_KEYS];
/* Collations to pass to the support functions */
Oid supportCollation[INDEX_MAX_KEYS];
} GISTSTATE;
/*
* During a GiST index search, we must maintain a queue of unvisited items,
* which can be either individual heap tuples or whole index pages. If it
* is an ordered search, the unvisited items should be visited in distance
* order. Unvisited items at the same distance should be visited in
* depth-first order, that is heap items first, then lower index pages, then
* upper index pages; this rule avoids doing extra work during a search that
* ends early due to LIMIT.
*
* To perform an ordered search, we use a pairing heap to manage the
* distance-order queue. In a non-ordered search (no order-by operators),
* we use it to return heap tuples before unvisited index pages, to
* ensure depth-first order, but all entries are otherwise considered
* equal.
*/
/* Individual heap tuple to be visited */
typedef struct GISTSearchHeapItem
{
ItemPointerData heapPtr;
bool recheck; /* T if quals must be rechecked */
Phase 2 of pgindent updates. Change pg_bsd_indent to follow upstream rules for placement of comments to the right of code, and remove pgindent hack that caused comments following #endif to not obey the general rule. Commit e3860ffa4dd0dad0dd9eea4be9cc1412373a8c89 wasn't actually using the published version of pg_bsd_indent, but a hacked-up version that tried to minimize the amount of movement of comments to the right of code. The situation of interest is where such a comment has to be moved to the right of its default placement at column 33 because there's code there. BSD indent has always moved right in units of tab stops in such cases --- but in the previous incarnation, indent was working in 8-space tab stops, while now it knows we use 4-space tabs. So the net result is that in about half the cases, such comments are placed one tab stop left of before. This is better all around: it leaves more room on the line for comment text, and it means that in such cases the comment uniformly starts at the next 4-space tab stop after the code, rather than sometimes one and sometimes two tabs after. Also, ensure that comments following #endif are indented the same as comments following other preprocessor commands such as #else. That inconsistency turns out to have been self-inflicted damage from a poorly-thought-through post-indent "fixup" in pgindent. This patch is much less interesting than the first round of indent changes, but also bulkier, so I thought it best to separate the effects. Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
2017-06-21 21:18:54 +02:00
bool recheckDistances; /* T if distances must be rechecked */
HeapTuple recontup; /* data reconstructed from the index, used in
* index-only scans */
OffsetNumber offnum; /* track offset in page to mark tuple as
* LP_DEAD */
} GISTSearchHeapItem;
/* Unvisited item, either index page or heap tuple */
typedef struct GISTSearchItem
{
pairingheap_node phNode;
BlockNumber blkno; /* index page number, or InvalidBlockNumber */
union
{
2011-04-10 17:42:00 +02:00
GistNSN parentlsn; /* parent page's LSN, if index page */
/* we must store parentlsn to detect whether a split occurred */
GISTSearchHeapItem heap; /* heap info, if heap tuple */
} data;
Phase 2 of pgindent updates. Change pg_bsd_indent to follow upstream rules for placement of comments to the right of code, and remove pgindent hack that caused comments following #endif to not obey the general rule. Commit e3860ffa4dd0dad0dd9eea4be9cc1412373a8c89 wasn't actually using the published version of pg_bsd_indent, but a hacked-up version that tried to minimize the amount of movement of comments to the right of code. The situation of interest is where such a comment has to be moved to the right of its default placement at column 33 because there's code there. BSD indent has always moved right in units of tab stops in such cases --- but in the previous incarnation, indent was working in 8-space tab stops, while now it knows we use 4-space tabs. So the net result is that in about half the cases, such comments are placed one tab stop left of before. This is better all around: it leaves more room on the line for comment text, and it means that in such cases the comment uniformly starts at the next 4-space tab stop after the code, rather than sometimes one and sometimes two tabs after. Also, ensure that comments following #endif are indented the same as comments following other preprocessor commands such as #else. That inconsistency turns out to have been self-inflicted damage from a poorly-thought-through post-indent "fixup" in pgindent. This patch is much less interesting than the first round of indent changes, but also bulkier, so I thought it best to separate the effects. Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
2017-06-21 21:18:54 +02:00
double distances[FLEXIBLE_ARRAY_MEMBER]; /* numberOfOrderBys
* entries */
2011-04-10 17:42:00 +02:00
} GISTSearchItem;
2011-04-10 17:42:00 +02:00
#define GISTSearchItemIsHeap(item) ((item).blkno == InvalidBlockNumber)
#define SizeOfGISTSearchItem(n_distances) (offsetof(GISTSearchItem, distances) + sizeof(double) * (n_distances))
/*
* GISTScanOpaqueData: private state for a scan of a GiST index
*/
typedef struct GISTScanOpaqueData
{
GISTSTATE *giststate; /* index information, see above */
Oid *orderByTypes; /* datatypes of ORDER BY expressions */
pairingheap *queue; /* queue of unvisited items */
MemoryContext queueCxt; /* context holding the queue */
bool qual_ok; /* false if qual can never be satisfied */
bool firstCall; /* true until first gistgettuple call */
/* pre-allocated workspace arrays */
double *distances; /* output area for gistindex_keytest */
/* info about killed items if any (killedItems is NULL if never used) */
OffsetNumber *killedItems; /* offset numbers of killed items */
int numKilled; /* number of currently stored items */
BlockNumber curBlkno; /* current number of block */
GistNSN curPageLSN; /* pos in the WAL stream when page was read */
/* In a non-ordered search, returnable heap items are stored here: */
GISTSearchHeapItem pageData[BLCKSZ / sizeof(IndexTupleData)];
OffsetNumber nPageData; /* number of valid items in array */
OffsetNumber curPageData; /* next item to return */
MemoryContext pageDataCxt; /* context holding the fetched tuples, for
2015-05-24 03:35:49 +02:00
* index-only scans */
} GISTScanOpaqueData;
typedef GISTScanOpaqueData *GISTScanOpaque;
/* despite the name, gistxlogPage is not part of any xlog record */
2005-10-15 04:49:52 +02:00
typedef struct gistxlogPage
{
BlockNumber blkno;
int num; /* number of index tuples following */
2005-10-15 04:49:52 +02:00
} gistxlogPage;
/* SplitedPageLayout - gistSplit function result */
2005-10-15 04:49:52 +02:00
typedef struct SplitedPageLayout
{
gistxlogPage block;
IndexTupleData *list;
int lenlist;
2006-10-04 02:30:14 +02:00
IndexTuple itup; /* union key for page */
Page page; /* to operate */
2005-10-15 04:49:52 +02:00
Buffer buffer; /* to write after all proceed */
2005-10-15 04:49:52 +02:00
struct SplitedPageLayout *next;
} SplitedPageLayout;
/*
* GISTInsertStack used for locking buffers and transfer arguments during
* insertion
*/
2005-10-15 04:49:52 +02:00
typedef struct GISTInsertStack
{
/* current page */
2005-10-15 04:49:52 +02:00
BlockNumber blkno;
Buffer buffer;
Page page;
2005-10-15 04:49:52 +02:00
/*
2011-04-10 17:42:00 +02:00
* log sequence number from page->lsn to recognize page update and compare
* it with page's nsn to recognize page split
2005-10-15 04:49:52 +02:00
*/
GistNSN lsn;
2005-10-15 04:49:52 +02:00
Detect internal GiST page splits correctly during index build. As we descend the GiST tree during insertion, we modify any downlinks on the way down to include the new tuple we're about to insert (if they don't cover it already). Modifying an existing downlink might cause an internal page to split, if the new downlink tuple is larger than the old one. If that happens, we need to back up to the parent and re-choose a page to insert to. We used to detect that situation, thanks to the NSN-LSN interlock normally used to detect concurrent page splits, but that got broken by commit 9155580fd5. With that commit, we now use a dummy constant LSN value for every page during index build, so the LSN-NSN interlock no longer works. I thought that was OK because there can't be any other backends modifying the index during index build, but missed that the insertion itself can modify the page we're inserting to. The consequence was that we would sometimes insert the new tuple to an incorrect page, one whose downlink doesn't cover the new tuple. To fix, add a flag to the stack that keeps track of the state while descending tree, to indicate that a page was split, and that we need to retry the descend from the parent. Thomas Munro first reported that the contrib/intarray regression test was failing occasionally on the buildfarm after commit 9155580fd5. The failure was intermittent, because the gistchoose() function is not deterministic, and would only occasionally create the right circumstances for this bug to cause the failure. Patch by Anastasia Lubennikova, with some changes by me to make it work correctly also when the internal page split also causes the "grandparent" to be split. Discussion: https://www.postgresql.org/message-id/CA%2BhUKGJRzLo7tZExWfSbwM3XuK7aAK7FhdBV0FLkbUG%2BW0v0zg%40mail.gmail.com
2019-05-14 12:18:44 +02:00
/*
* If set, we split the page while descending the tree to find an
* insertion target. It means that we need to retry from the parent,
* because the downlink of this page might no longer cover the new key.
*/
bool retry_from_parent;
/* offset of the downlink in the parent page, that points to this page */
OffsetNumber downlinkoffnum;
Rewrite the GiST insertion logic so that we don't need the post-recovery cleanup stage to finish incomplete inserts or splits anymore. There was two reasons for the cleanup step: 1. When a new tuple was inserted to a leaf page, the downlink in the parent needed to be updated to contain (ie. to be consistent with) the new key. Updating the parent in turn might require recursively updating the parent of the parent. We now handle that by updating the parent while traversing down the tree, so that when we insert the leaf tuple, all the parents are already consistent with the new key, and the tree is consistent at every step. 2. When a page is split, we need to insert the downlink for the new right page(s), and update the downlink for the original page to not include keys that moved to the right page(s). We now handle that by setting a new flag, F_FOLLOW_RIGHT, on the non-rightmost pages in the split. When that flag is set, scans always follow the rightlink, regardless of the NSN mechanism used to detect concurrent page splits. That way the tree is consistent right after split, even though the downlink is still missing. This is very similar to the way B-tree splits are handled. When the downlink is inserted in the parent, the flag is cleared. To keep the insertion algorithm simple, when an insertion sees an incomplete split, indicated by the F_FOLLOW_RIGHT flag, it finishes the split before doing anything else. These changes allow removing the whole "invalid tuple" mechanism, but I retained the scan code to still follow invalid tuples correctly. While we don't create any such tuples anymore, we want to handle them gracefully in case you pg_upgrade a GiST index that has them. If we encounter any on an insert, though, we just throw an error saying that you need to REINDEX. The issue that got me into doing this is that if you did a checkpoint while an insert or split was in progress, and the checkpoint finishes quickly so that there is no WAL record related to the insert between RedoRecPtr and the checkpoint record, recovery from that checkpoint would not know to finish the incomplete insert. IOW, we have the same issue we solved with the rm_safe_restartpoint mechanism during normal operation too. It's highly unlikely to happen in practice, and this fix is far too large to backpatch, so we're just going to live with in previous versions, but this refactoring fixes it going forward. With this patch, you don't get the annoying 'index "FOO" needs VACUUM or REINDEX to finish crash recovery' notices anymore if you crash at an unfortunate moment.
2010-12-23 15:03:08 +01:00
/* pointer to parent */
2005-10-15 04:49:52 +02:00
struct GISTInsertStack *parent;
} GISTInsertStack;
/* Working state and results for multi-column split logic in gistsplit.c */
2006-10-04 02:30:14 +02:00
typedef struct GistSplitVector
{
GIST_SPLITVEC splitVector; /* passed to/from user PickSplit method */
Phase 2 of pgindent updates. Change pg_bsd_indent to follow upstream rules for placement of comments to the right of code, and remove pgindent hack that caused comments following #endif to not obey the general rule. Commit e3860ffa4dd0dad0dd9eea4be9cc1412373a8c89 wasn't actually using the published version of pg_bsd_indent, but a hacked-up version that tried to minimize the amount of movement of comments to the right of code. The situation of interest is where such a comment has to be moved to the right of its default placement at column 33 because there's code there. BSD indent has always moved right in units of tab stops in such cases --- but in the previous incarnation, indent was working in 8-space tab stops, while now it knows we use 4-space tabs. So the net result is that in about half the cases, such comments are placed one tab stop left of before. This is better all around: it leaves more room on the line for comment text, and it means that in such cases the comment uniformly starts at the next 4-space tab stop after the code, rather than sometimes one and sometimes two tabs after. Also, ensure that comments following #endif are indented the same as comments following other preprocessor commands such as #else. That inconsistency turns out to have been self-inflicted damage from a poorly-thought-through post-indent "fixup" in pgindent. This patch is much less interesting than the first round of indent changes, but also bulkier, so I thought it best to separate the effects. Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
2017-06-21 21:18:54 +02:00
Datum spl_lattr[INDEX_MAX_KEYS]; /* Union of subkeys in
* splitVector.spl_left */
2006-10-04 02:30:14 +02:00
bool spl_lisnull[INDEX_MAX_KEYS];
Phase 2 of pgindent updates. Change pg_bsd_indent to follow upstream rules for placement of comments to the right of code, and remove pgindent hack that caused comments following #endif to not obey the general rule. Commit e3860ffa4dd0dad0dd9eea4be9cc1412373a8c89 wasn't actually using the published version of pg_bsd_indent, but a hacked-up version that tried to minimize the amount of movement of comments to the right of code. The situation of interest is where such a comment has to be moved to the right of its default placement at column 33 because there's code there. BSD indent has always moved right in units of tab stops in such cases --- but in the previous incarnation, indent was working in 8-space tab stops, while now it knows we use 4-space tabs. So the net result is that in about half the cases, such comments are placed one tab stop left of before. This is better all around: it leaves more room on the line for comment text, and it means that in such cases the comment uniformly starts at the next 4-space tab stop after the code, rather than sometimes one and sometimes two tabs after. Also, ensure that comments following #endif are indented the same as comments following other preprocessor commands such as #else. That inconsistency turns out to have been self-inflicted damage from a poorly-thought-through post-indent "fixup" in pgindent. This patch is much less interesting than the first round of indent changes, but also bulkier, so I thought it best to separate the effects. Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
2017-06-21 21:18:54 +02:00
Datum spl_rattr[INDEX_MAX_KEYS]; /* Union of subkeys in
* splitVector.spl_right */
2006-10-04 02:30:14 +02:00
bool spl_risnull[INDEX_MAX_KEYS];
bool *spl_dontcare; /* flags tuples which could go to either side
* of the split for zero penalty */
} GistSplitVector;
2005-10-15 04:49:52 +02:00
typedef struct
{
Relation r;
Relation heapRel;
Size freespace; /* free space to be left */
bool is_build;
Rewrite the GiST insertion logic so that we don't need the post-recovery cleanup stage to finish incomplete inserts or splits anymore. There was two reasons for the cleanup step: 1. When a new tuple was inserted to a leaf page, the downlink in the parent needed to be updated to contain (ie. to be consistent with) the new key. Updating the parent in turn might require recursively updating the parent of the parent. We now handle that by updating the parent while traversing down the tree, so that when we insert the leaf tuple, all the parents are already consistent with the new key, and the tree is consistent at every step. 2. When a page is split, we need to insert the downlink for the new right page(s), and update the downlink for the original page to not include keys that moved to the right page(s). We now handle that by setting a new flag, F_FOLLOW_RIGHT, on the non-rightmost pages in the split. When that flag is set, scans always follow the rightlink, regardless of the NSN mechanism used to detect concurrent page splits. That way the tree is consistent right after split, even though the downlink is still missing. This is very similar to the way B-tree splits are handled. When the downlink is inserted in the parent, the flag is cleared. To keep the insertion algorithm simple, when an insertion sees an incomplete split, indicated by the F_FOLLOW_RIGHT flag, it finishes the split before doing anything else. These changes allow removing the whole "invalid tuple" mechanism, but I retained the scan code to still follow invalid tuples correctly. While we don't create any such tuples anymore, we want to handle them gracefully in case you pg_upgrade a GiST index that has them. If we encounter any on an insert, though, we just throw an error saying that you need to REINDEX. The issue that got me into doing this is that if you did a checkpoint while an insert or split was in progress, and the checkpoint finishes quickly so that there is no WAL record related to the insert between RedoRecPtr and the checkpoint record, recovery from that checkpoint would not know to finish the incomplete insert. IOW, we have the same issue we solved with the rm_safe_restartpoint mechanism during normal operation too. It's highly unlikely to happen in practice, and this fix is far too large to backpatch, so we're just going to live with in previous versions, but this refactoring fixes it going forward. With this patch, you don't get the annoying 'index "FOO" needs VACUUM or REINDEX to finish crash recovery' notices anymore if you crash at an unfortunate moment.
2010-12-23 15:03:08 +01:00
GISTInsertStack *stack;
} GISTInsertState;
/* root page of a gist index */
#define GIST_ROOT_BLKNO 0
/*
* Before PostgreSQL 9.1, we used to rely on so-called "invalid tuples" on
* inner pages to finish crash recovery of incomplete page splits. If a crash
Rewrite the GiST insertion logic so that we don't need the post-recovery cleanup stage to finish incomplete inserts or splits anymore. There was two reasons for the cleanup step: 1. When a new tuple was inserted to a leaf page, the downlink in the parent needed to be updated to contain (ie. to be consistent with) the new key. Updating the parent in turn might require recursively updating the parent of the parent. We now handle that by updating the parent while traversing down the tree, so that when we insert the leaf tuple, all the parents are already consistent with the new key, and the tree is consistent at every step. 2. When a page is split, we need to insert the downlink for the new right page(s), and update the downlink for the original page to not include keys that moved to the right page(s). We now handle that by setting a new flag, F_FOLLOW_RIGHT, on the non-rightmost pages in the split. When that flag is set, scans always follow the rightlink, regardless of the NSN mechanism used to detect concurrent page splits. That way the tree is consistent right after split, even though the downlink is still missing. This is very similar to the way B-tree splits are handled. When the downlink is inserted in the parent, the flag is cleared. To keep the insertion algorithm simple, when an insertion sees an incomplete split, indicated by the F_FOLLOW_RIGHT flag, it finishes the split before doing anything else. These changes allow removing the whole "invalid tuple" mechanism, but I retained the scan code to still follow invalid tuples correctly. While we don't create any such tuples anymore, we want to handle them gracefully in case you pg_upgrade a GiST index that has them. If we encounter any on an insert, though, we just throw an error saying that you need to REINDEX. The issue that got me into doing this is that if you did a checkpoint while an insert or split was in progress, and the checkpoint finishes quickly so that there is no WAL record related to the insert between RedoRecPtr and the checkpoint record, recovery from that checkpoint would not know to finish the incomplete insert. IOW, we have the same issue we solved with the rm_safe_restartpoint mechanism during normal operation too. It's highly unlikely to happen in practice, and this fix is far too large to backpatch, so we're just going to live with in previous versions, but this refactoring fixes it going forward. With this patch, you don't get the annoying 'index "FOO" needs VACUUM or REINDEX to finish crash recovery' notices anymore if you crash at an unfortunate moment.
2010-12-23 15:03:08 +01:00
* happened in the middle of a page split, so that the downlink pointers were
* not yet inserted, crash recovery inserted a special downlink pointer. The
* semantics of an invalid tuple was that it if you encounter one in a scan,
* it must always be followed, because we don't know if the tuples on the
* child page match or not.
*
* We no longer create such invalid tuples, we now mark the left-half of such
* an incomplete split with the F_FOLLOW_RIGHT flag instead, and finish the
* split properly the next time we need to insert on that page. To retain
* on-disk compatibility for the sake of pg_upgrade, we still store 0xffff as
* the offset number of all inner tuples. If we encounter any invalid tuples
* with 0xfffe during insertion, we throw an error, though scans still handle
* them. You should only encounter invalid tuples if you pg_upgrade a pre-9.1
* gist index which already has invalid tuples in it because of a crash. That
* should be rare, and you are recommended to REINDEX anyway if you have any
* invalid tuples in an index, so throwing an error is as far as we go with
* supporting that.
*/
#define TUPLE_IS_VALID 0xffff
#define TUPLE_IS_INVALID 0xfffe
#define GistTupleIsInvalid(itup) ( ItemPointerGetOffsetNumber( &((itup)->t_tid) ) == TUPLE_IS_INVALID )
#define GistTupleSetValid(itup) ItemPointerSetOffsetNumber( &((itup)->t_tid), TUPLE_IS_VALID )
/*
* A buffer attached to an internal node, used when building an index in
* buffering mode.
*/
typedef struct
{
BlockNumber nodeBlocknum; /* index block # this buffer is for */
int32 blocksCount; /* current # of blocks occupied by buffer */
BlockNumber pageBlocknum; /* temporary file block # */
Phase 2 of pgindent updates. Change pg_bsd_indent to follow upstream rules for placement of comments to the right of code, and remove pgindent hack that caused comments following #endif to not obey the general rule. Commit e3860ffa4dd0dad0dd9eea4be9cc1412373a8c89 wasn't actually using the published version of pg_bsd_indent, but a hacked-up version that tried to minimize the amount of movement of comments to the right of code. The situation of interest is where such a comment has to be moved to the right of its default placement at column 33 because there's code there. BSD indent has always moved right in units of tab stops in such cases --- but in the previous incarnation, indent was working in 8-space tab stops, while now it knows we use 4-space tabs. So the net result is that in about half the cases, such comments are placed one tab stop left of before. This is better all around: it leaves more room on the line for comment text, and it means that in such cases the comment uniformly starts at the next 4-space tab stop after the code, rather than sometimes one and sometimes two tabs after. Also, ensure that comments following #endif are indented the same as comments following other preprocessor commands such as #else. That inconsistency turns out to have been self-inflicted damage from a poorly-thought-through post-indent "fixup" in pgindent. This patch is much less interesting than the first round of indent changes, but also bulkier, so I thought it best to separate the effects. Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
2017-06-21 21:18:54 +02:00
GISTNodeBufferPage *pageBuffer; /* in-memory buffer page */
/* is this buffer queued for emptying? */
bool queuedForEmptying;
/* is this a temporary copy, not in the hash table? */
bool isTemp;
int level; /* 0 == leaf */
} GISTNodeBuffer;
/*
* Does specified level have buffers? (Beware of multiple evaluation of
* arguments.)
*/
#define LEVEL_HAS_BUFFERS(nlevel, gfbb) \
((nlevel) != 0 && (nlevel) % (gfbb)->levelStep == 0 && \
(nlevel) != (gfbb)->rootlevel)
/* Is specified buffer at least half-filled (should be queued for emptying)? */
#define BUFFER_HALF_FILLED(nodeBuffer, gfbb) \
((nodeBuffer)->blocksCount > (gfbb)->pagesPerBuffer / 2)
/*
* Is specified buffer full? Our buffers can actually grow indefinitely,
* beyond the "maximum" size, so this just means whether the buffer has grown
* beyond the nominal maximum size.
*/
#define BUFFER_OVERFLOWED(nodeBuffer, gfbb) \
((nodeBuffer)->blocksCount > (gfbb)->pagesPerBuffer)
/*
* Data structure with general information about build buffers.
*/
typedef struct GISTBuildBuffers
{
/* Persistent memory context for the buffers and metadata. */
MemoryContext context;
BufFile *pfile; /* Temporary file to store buffers in */
long nFileBlocks; /* Current size of the temporary file */
/*
* resizable array of free blocks.
*/
long *freeBlocks;
int nFreeBlocks; /* # of currently free blocks in the array */
int freeBlocksLen; /* current allocated length of the array */
/* Hash for buffers by block number */
HTAB *nodeBuffersTab;
/* List of buffers scheduled for emptying */
List *bufferEmptyingQueue;
/*
* Parameters to the buffering build algorithm. levelStep determines which
* levels in the tree have buffers, and pagesPerBuffer determines how
* large each buffer is.
*/
int levelStep;
int pagesPerBuffer;
/* Array of lists of buffers on each level, for final emptying */
List **buffersOnLevels;
int buffersOnLevelsLen;
/*
* Dynamically-sized array of buffers that currently have their last page
* loaded in main memory.
*/
GISTNodeBuffer **loadedBuffers;
Phase 2 of pgindent updates. Change pg_bsd_indent to follow upstream rules for placement of comments to the right of code, and remove pgindent hack that caused comments following #endif to not obey the general rule. Commit e3860ffa4dd0dad0dd9eea4be9cc1412373a8c89 wasn't actually using the published version of pg_bsd_indent, but a hacked-up version that tried to minimize the amount of movement of comments to the right of code. The situation of interest is where such a comment has to be moved to the right of its default placement at column 33 because there's code there. BSD indent has always moved right in units of tab stops in such cases --- but in the previous incarnation, indent was working in 8-space tab stops, while now it knows we use 4-space tabs. So the net result is that in about half the cases, such comments are placed one tab stop left of before. This is better all around: it leaves more room on the line for comment text, and it means that in such cases the comment uniformly starts at the next 4-space tab stop after the code, rather than sometimes one and sometimes two tabs after. Also, ensure that comments following #endif are indented the same as comments following other preprocessor commands such as #else. That inconsistency turns out to have been self-inflicted damage from a poorly-thought-through post-indent "fixup" in pgindent. This patch is much less interesting than the first round of indent changes, but also bulkier, so I thought it best to separate the effects. Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
2017-06-21 21:18:54 +02:00
int loadedBuffersCount; /* # of entries in loadedBuffers */
int loadedBuffersLen; /* allocated size of loadedBuffers */
/* Level of the current root node (= height of the index tree - 1) */
int rootlevel;
} GISTBuildBuffers;
/*
* Storage type for GiST's reloptions
*/
typedef struct GiSTOptions
{
int32 vl_len_; /* varlena header (do not touch directly!) */
int fillfactor; /* page fill factor in percent (0..100) */
int bufferingModeOffset; /* use buffering build? */
} GiSTOptions;
/* gist.c */
extern void gistbuildempty(Relation index);
extern bool gistinsert(Relation r, Datum *values, bool *isnull,
ItemPointer ht_ctid, Relation heapRel,
IndexUniqueCheck checkUnique,
struct IndexInfo *indexInfo);
extern MemoryContext createTempGistContext(void);
extern GISTSTATE *initGISTstate(Relation index);
extern void freeGISTstate(GISTSTATE *giststate);
extern void gistdoinsert(Relation r,
IndexTuple itup,
Size freespace,
GISTSTATE *GISTstate,
Relation heapRel,
bool is_build);
/* A List of these is returned from gistplacetopage() in *splitinfo */
typedef struct
{
Buffer buf; /* the split page "half" */
IndexTuple downlink; /* downlink for this half. */
} GISTPageSplitInfo;
extern bool gistplacetopage(Relation rel, Size freespace, GISTSTATE *giststate,
Buffer buffer,
IndexTuple *itup, int ntup,
OffsetNumber oldoffnum, BlockNumber *newblkno,
Buffer leftchildbuf,
List **splitinfo,
bool markleftchild,
Relation heapRel,
bool is_build);
extern SplitedPageLayout *gistSplit(Relation r, Page page, IndexTuple *itup,
int len, GISTSTATE *giststate);
2005-10-15 04:49:52 +02:00
/* gistxlog.c */
extern XLogRecPtr gistXLogPageDelete(Buffer buffer,
TransactionId xid, Buffer parentBuffer,
OffsetNumber downlinkOffset);
extern void gistXLogPageReuse(Relation rel, BlockNumber blkno,
TransactionId latestRemovedXid);
extern XLogRecPtr gistXLogUpdate(Buffer buffer,
Rewrite the GiST insertion logic so that we don't need the post-recovery cleanup stage to finish incomplete inserts or splits anymore. There was two reasons for the cleanup step: 1. When a new tuple was inserted to a leaf page, the downlink in the parent needed to be updated to contain (ie. to be consistent with) the new key. Updating the parent in turn might require recursively updating the parent of the parent. We now handle that by updating the parent while traversing down the tree, so that when we insert the leaf tuple, all the parents are already consistent with the new key, and the tree is consistent at every step. 2. When a page is split, we need to insert the downlink for the new right page(s), and update the downlink for the original page to not include keys that moved to the right page(s). We now handle that by setting a new flag, F_FOLLOW_RIGHT, on the non-rightmost pages in the split. When that flag is set, scans always follow the rightlink, regardless of the NSN mechanism used to detect concurrent page splits. That way the tree is consistent right after split, even though the downlink is still missing. This is very similar to the way B-tree splits are handled. When the downlink is inserted in the parent, the flag is cleared. To keep the insertion algorithm simple, when an insertion sees an incomplete split, indicated by the F_FOLLOW_RIGHT flag, it finishes the split before doing anything else. These changes allow removing the whole "invalid tuple" mechanism, but I retained the scan code to still follow invalid tuples correctly. While we don't create any such tuples anymore, we want to handle them gracefully in case you pg_upgrade a GiST index that has them. If we encounter any on an insert, though, we just throw an error saying that you need to REINDEX. The issue that got me into doing this is that if you did a checkpoint while an insert or split was in progress, and the checkpoint finishes quickly so that there is no WAL record related to the insert between RedoRecPtr and the checkpoint record, recovery from that checkpoint would not know to finish the incomplete insert. IOW, we have the same issue we solved with the rm_safe_restartpoint mechanism during normal operation too. It's highly unlikely to happen in practice, and this fix is far too large to backpatch, so we're just going to live with in previous versions, but this refactoring fixes it going forward. With this patch, you don't get the annoying 'index "FOO" needs VACUUM or REINDEX to finish crash recovery' notices anymore if you crash at an unfortunate moment.
2010-12-23 15:03:08 +01:00
OffsetNumber *todelete, int ntodelete,
2011-04-10 17:42:00 +02:00
IndexTuple *itup, int ntup,
Rewrite the GiST insertion logic so that we don't need the post-recovery cleanup stage to finish incomplete inserts or splits anymore. There was two reasons for the cleanup step: 1. When a new tuple was inserted to a leaf page, the downlink in the parent needed to be updated to contain (ie. to be consistent with) the new key. Updating the parent in turn might require recursively updating the parent of the parent. We now handle that by updating the parent while traversing down the tree, so that when we insert the leaf tuple, all the parents are already consistent with the new key, and the tree is consistent at every step. 2. When a page is split, we need to insert the downlink for the new right page(s), and update the downlink for the original page to not include keys that moved to the right page(s). We now handle that by setting a new flag, F_FOLLOW_RIGHT, on the non-rightmost pages in the split. When that flag is set, scans always follow the rightlink, regardless of the NSN mechanism used to detect concurrent page splits. That way the tree is consistent right after split, even though the downlink is still missing. This is very similar to the way B-tree splits are handled. When the downlink is inserted in the parent, the flag is cleared. To keep the insertion algorithm simple, when an insertion sees an incomplete split, indicated by the F_FOLLOW_RIGHT flag, it finishes the split before doing anything else. These changes allow removing the whole "invalid tuple" mechanism, but I retained the scan code to still follow invalid tuples correctly. While we don't create any such tuples anymore, we want to handle them gracefully in case you pg_upgrade a GiST index that has them. If we encounter any on an insert, though, we just throw an error saying that you need to REINDEX. The issue that got me into doing this is that if you did a checkpoint while an insert or split was in progress, and the checkpoint finishes quickly so that there is no WAL record related to the insert between RedoRecPtr and the checkpoint record, recovery from that checkpoint would not know to finish the incomplete insert. IOW, we have the same issue we solved with the rm_safe_restartpoint mechanism during normal operation too. It's highly unlikely to happen in practice, and this fix is far too large to backpatch, so we're just going to live with in previous versions, but this refactoring fixes it going forward. With this patch, you don't get the annoying 'index "FOO" needs VACUUM or REINDEX to finish crash recovery' notices anymore if you crash at an unfortunate moment.
2010-12-23 15:03:08 +01:00
Buffer leftchild);
extern XLogRecPtr gistXLogDelete(Buffer buffer, OffsetNumber *todelete,
int ntodelete, TransactionId latestRemovedXid);
extern XLogRecPtr gistXLogSplit(bool page_is_leaf,
Rewrite the GiST insertion logic so that we don't need the post-recovery cleanup stage to finish incomplete inserts or splits anymore. There was two reasons for the cleanup step: 1. When a new tuple was inserted to a leaf page, the downlink in the parent needed to be updated to contain (ie. to be consistent with) the new key. Updating the parent in turn might require recursively updating the parent of the parent. We now handle that by updating the parent while traversing down the tree, so that when we insert the leaf tuple, all the parents are already consistent with the new key, and the tree is consistent at every step. 2. When a page is split, we need to insert the downlink for the new right page(s), and update the downlink for the original page to not include keys that moved to the right page(s). We now handle that by setting a new flag, F_FOLLOW_RIGHT, on the non-rightmost pages in the split. When that flag is set, scans always follow the rightlink, regardless of the NSN mechanism used to detect concurrent page splits. That way the tree is consistent right after split, even though the downlink is still missing. This is very similar to the way B-tree splits are handled. When the downlink is inserted in the parent, the flag is cleared. To keep the insertion algorithm simple, when an insertion sees an incomplete split, indicated by the F_FOLLOW_RIGHT flag, it finishes the split before doing anything else. These changes allow removing the whole "invalid tuple" mechanism, but I retained the scan code to still follow invalid tuples correctly. While we don't create any such tuples anymore, we want to handle them gracefully in case you pg_upgrade a GiST index that has them. If we encounter any on an insert, though, we just throw an error saying that you need to REINDEX. The issue that got me into doing this is that if you did a checkpoint while an insert or split was in progress, and the checkpoint finishes quickly so that there is no WAL record related to the insert between RedoRecPtr and the checkpoint record, recovery from that checkpoint would not know to finish the incomplete insert. IOW, we have the same issue we solved with the rm_safe_restartpoint mechanism during normal operation too. It's highly unlikely to happen in practice, and this fix is far too large to backpatch, so we're just going to live with in previous versions, but this refactoring fixes it going forward. With this patch, you don't get the annoying 'index "FOO" needs VACUUM or REINDEX to finish crash recovery' notices anymore if you crash at an unfortunate moment.
2010-12-23 15:03:08 +01:00
SplitedPageLayout *dist,
BlockNumber origrlink, GistNSN oldnsn,
Buffer leftchild, bool markfollowright);
/* gistget.c */
extern bool gistgettuple(IndexScanDesc scan, ScanDirection dir);
extern int64 gistgetbitmap(IndexScanDesc scan, TIDBitmap *tbm);
extern bool gistcanreturn(Relation index, int attno);
/* gistvalidate.c */
extern bool gistvalidate(Oid opclassoid);
/* gistutil.c */
#define GiSTPageSize \
2006-10-04 02:30:14 +02:00
( BLCKSZ - SizeOfPageHeaderData - MAXALIGN(sizeof(GISTPageOpaqueData)) )
#define GIST_MIN_FILLFACTOR 10
#define GIST_DEFAULT_FILLFACTOR 90
extern bytea *gistoptions(Datum reloptions, bool validate);
extern bool gistproperty(Oid index_oid, int attno,
IndexAMProperty prop, const char *propname,
bool *res, bool *isnull);
extern bool gistfitpage(IndexTuple *itvec, int len);
extern bool gistnospace(Page page, IndexTuple *itvec, int len, OffsetNumber todelete, Size freespace);
extern void gistcheckpage(Relation rel, Buffer buf);
2005-10-15 04:49:52 +02:00
extern Buffer gistNewBuffer(Relation r);
extern bool gistPageRecyclable(Page page);
extern void gistfillbuffer(Page page, IndexTuple *itup, int len,
OffsetNumber off);
extern IndexTuple *gistextractpage(Page page, int *len /* out */ );
2005-10-15 04:49:52 +02:00
extern IndexTuple *gistjoinvector(
IndexTuple *itvec, int *len,
IndexTuple *additvec, int addlen);
2006-10-04 02:30:14 +02:00
extern IndexTupleData *gistfillitupvec(IndexTuple *vec, int veclen, int *memlen);
extern IndexTuple gistunion(Relation r, IndexTuple *itvec,
2005-10-15 04:49:52 +02:00
int len, GISTSTATE *giststate);
extern IndexTuple gistgetadjusted(Relation r,
2005-10-15 04:49:52 +02:00
IndexTuple oldtup,
IndexTuple addtup,
GISTSTATE *giststate);
extern IndexTuple gistFormTuple(GISTSTATE *giststate,
Relation r, Datum *attdata, bool *isnull, bool isleaf);
extern OffsetNumber gistchoose(Relation r, Page p,
2005-10-15 04:49:52 +02:00
IndexTuple it,
GISTSTATE *giststate);
extern void GISTInitBuffer(Buffer b, uint32 f);
extern void gistdentryinit(GISTSTATE *giststate, int nkey, GISTENTRY *e,
Datum k, Relation r, Page pg, OffsetNumber o,
bool l, bool isNull);
extern float gistpenalty(GISTSTATE *giststate, int attno,
2006-10-04 02:30:14 +02:00
GISTENTRY *key1, bool isNull1,
GISTENTRY *key2, bool isNull2);
Repair bugs in GiST page splitting code for multi-column indexes. When considering a non-last column in a multi-column GiST index, gistsplit.c tries to improve on the split chosen by the opclass-specific pickSplit function by considering penalties for the next column. However, there were two bugs in this code: it failed to recompute the union keys for the leftmost index columns, even though these might well change after reassigning tuples; and it included the old union keys in the recomputation for the columns it did recompute, so that those keys couldn't get smaller even if they should. The first problem could result in an invalid index in which searches wouldn't find index entries that are in fact present; the second would make the index less efficient to search. Both of these errors were caused by misuse of gistMakeUnionItVec, whose API was designed in a way that just begged such errors to be made. There is no situation in which it's safe or useful to compute the union keys for a subset of the index columns, and there is no caller that wants any previous union keys to be included in the computation; so the undocumented choice to treat the union keys as in/out rather than pure output parameters is a waste of code as well as being dangerous. Hence, rather than just making a minimal patch, I've changed the API of gistMakeUnionItVec to remove the "startkey" parameter (it now always processes all index columns) and treat the attr/isnull arrays as purely output parameters. In passing, also get rid of a couple of unnecessary and dangerous uses of static variables in gistutil.c. It's remarkable that the one in gistMakeUnionKey hasn't given us portability troubles before now, because in addition to posing a re-entrancy hazard, it was unsafely assuming that a static char[] array would have at least Datum alignment. Per investigation of a trouble report from Tomas Vondra. (There are also some bugs in contrib/btree_gist to be fixed, but that seems like material for a separate patch.) Back-patch to all supported branches.
2013-02-07 23:44:02 +01:00
extern void gistMakeUnionItVec(GISTSTATE *giststate, IndexTuple *itvec, int len,
2006-10-04 02:30:14 +02:00
Datum *attr, bool *isnull);
extern bool gistKeyIsEQ(GISTSTATE *giststate, int attno, Datum a, Datum b);
extern void gistDeCompressAtt(GISTSTATE *giststate, Relation r, IndexTuple tuple, Page p,
2006-10-04 02:30:14 +02:00
OffsetNumber o, GISTENTRY *attdata, bool *isnull);
extern HeapTuple gistFetchTuple(GISTSTATE *giststate, Relation r,
IndexTuple tuple);
2006-10-04 02:30:14 +02:00
extern void gistMakeUnionKey(GISTSTATE *giststate, int attno,
GISTENTRY *entry1, bool isnull1,
GISTENTRY *entry2, bool isnull2,
Datum *dst, bool *dstisnull);
extern XLogRecPtr gistGetFakeLSN(Relation rel);
/* gistvacuum.c */
extern IndexBulkDeleteResult *gistbulkdelete(IndexVacuumInfo *info,
IndexBulkDeleteResult *stats,
IndexBulkDeleteCallback callback,
void *callback_state);
extern IndexBulkDeleteResult *gistvacuumcleanup(IndexVacuumInfo *info,
IndexBulkDeleteResult *stats);
/* gistsplit.c */
2006-10-04 02:30:14 +02:00
extern void gistSplitByKey(Relation r, Page page, IndexTuple *itup,
int len, GISTSTATE *giststate,
GistSplitVector *v,
2006-10-04 02:30:14 +02:00
int attno);
/* gistbuild.c */
extern IndexBuildResult *gistbuild(Relation heap, Relation index,
struct IndexInfo *indexInfo);
extern void gistValidateBufferingOption(const char *value);
/* gistbuildbuffers.c */
extern GISTBuildBuffers *gistInitBuildBuffers(int pagesPerBuffer, int levelStep,
int maxLevel);
extern GISTNodeBuffer *gistGetNodeBuffer(GISTBuildBuffers *gfbb,
GISTSTATE *giststate,
BlockNumber blkno, int level);
extern void gistPushItupToNodeBuffer(GISTBuildBuffers *gfbb,
GISTNodeBuffer *nodeBuffer, IndexTuple item);
extern bool gistPopItupFromNodeBuffer(GISTBuildBuffers *gfbb,
GISTNodeBuffer *nodeBuffer, IndexTuple *item);
extern void gistFreeBuildBuffers(GISTBuildBuffers *gfbb);
extern void gistRelocateBuildBuffersOnSplit(GISTBuildBuffers *gfbb,
GISTSTATE *giststate, Relation r,
int level, Buffer buffer,
List *splitinfo);
extern void gistUnloadNodeBuffers(GISTBuildBuffers *gfbb);
Phase 2 of pgindent updates. Change pg_bsd_indent to follow upstream rules for placement of comments to the right of code, and remove pgindent hack that caused comments following #endif to not obey the general rule. Commit e3860ffa4dd0dad0dd9eea4be9cc1412373a8c89 wasn't actually using the published version of pg_bsd_indent, but a hacked-up version that tried to minimize the amount of movement of comments to the right of code. The situation of interest is where such a comment has to be moved to the right of its default placement at column 33 because there's code there. BSD indent has always moved right in units of tab stops in such cases --- but in the previous incarnation, indent was working in 8-space tab stops, while now it knows we use 4-space tabs. So the net result is that in about half the cases, such comments are placed one tab stop left of before. This is better all around: it leaves more room on the line for comment text, and it means that in such cases the comment uniformly starts at the next 4-space tab stop after the code, rather than sometimes one and sometimes two tabs after. Also, ensure that comments following #endif are indented the same as comments following other preprocessor commands such as #else. That inconsistency turns out to have been self-inflicted damage from a poorly-thought-through post-indent "fixup" in pgindent. This patch is much less interesting than the first round of indent changes, but also bulkier, so I thought it best to separate the effects. Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
2017-06-21 21:18:54 +02:00
#endif /* GIST_PRIVATE_H */