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postgresql/src/include/utils/relcache.h

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More cleanups of the include files - centralizing to simplify the -I's required to compile
1996-08-28 03:59:28 +02:00
/*-------------------------------------------------------------------------
*
Change my-function-name-- to my_function_name, and optimizer renames.
1999-02-14 00:22:53 +01:00
* relcache.h
Massive commit to run PGINDENT on all *.c and *.h files.
1997-09-07 07:04:48 +02:00
* Relation descriptor cache definitions.
More cleanups of the include files - centralizing to simplify the -I's required to compile
1996-08-28 03:59:28 +02:00
*
*
Update copyright for 2009.
2009-01-01 18:24:05 +01:00
* Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
Add: * Portions Copyright (c) 1996-2000, PostgreSQL, Inc to all files copyright Regents of Berkeley. Man, that's a lot of files.
2000-01-26 06:58:53 +01:00
* Portions Copyright (c) 1994, Regents of the University of California
More cleanups of the include files - centralizing to simplify the -I's required to compile
1996-08-28 03:59:28 +02:00
*
Update copyright for 2009.
2009-01-01 18:24:05 +01:00
* $PostgreSQL: pgsql/src/include/utils/relcache.h,v 1.63 2009/01/01 17:24:02 momjian Exp $
More cleanups of the include files - centralizing to simplify the -I's required to compile
1996-08-28 03:59:28 +02:00
*
*-------------------------------------------------------------------------
*/
Massive commit to run PGINDENT on all *.c and *.h files.
1997-09-07 07:04:48 +02:00
#ifndef RELCACHE_H
More cleanups of the include files - centralizing to simplify the -I's required to compile
1996-08-28 03:59:28 +02:00
#define RELCACHE_H
Improve our #include situation by moving pointer types away from the corresponding struct definitions. This allows other headers to avoid including certain highly-loaded headers such as rel.h and relscan.h, instead using just relcache.h, heapam.h or genam.h, which are more lightweight and thus cause less unnecessary dependencies.
2008-06-19 02:46:06 +02:00
#include "access/tupdesc.h"
#include "nodes/bitmapset.h"
#include "nodes/pg_list.h"
typedef struct RelationData *Relation;
/* ----------------
* RelationPtr is used in the executor to support index scans
* where we have to keep track of several index relations in an
* array. -cim 9/10/89
* ----------------
*/
typedef Relation *RelationPtr;
More cleanups of the include files - centralizing to simplify the -I's required to compile
1996-08-28 03:59:28 +02:00
/*
Change the relation_open protocol so that we obtain lock on a relation (table or index) before trying to open its relcache entry. This fixes race conditions in which someone else commits a change to the relation's catalog entries while we are in process of doing relcache load. Problems of that ilk have been reported sporadically for years, but it was not really practical to fix until recently --- for instance, the recent addition of WAL-log support for in-place updates helped. Along the way, remove pg_am.amconcurrent: all AMs are now expected to support concurrent update.
2006-07-31 22:09:10 +02:00
* Routines to open (lookup) and close a relcache entry
More cleanups of the include files - centralizing to simplify the -I's required to compile
1996-08-28 03:59:28 +02:00
*/
extern Relation RelationIdGetRelation(Oid relationId);
Another PGINDENT run that changes variable indenting and case label indenting. Also static variable indenting.
1997-09-08 04:41:22 +02:00
extern void RelationClose(Relation relation);
Reimplement parsing and storage of default expressions and constraint expressions in CREATE TABLE. There is no longer an emasculated expression syntax for these things; it's full a_expr for constraints, and b_expr for defaults (unfortunately the fact that NOT NULL is a part of the column constraint syntax causes a shift/reduce conflict if you try a_expr. Oh well --- at least parenthesized boolean expressions work now). Also, stored expression for a column default is not pre-coerced to the column type; we rely on transformInsertStatement to do that when the default is actually used. This means "f1 datetime default 'now'" behaves the way people usually expect it to. BTW, all the support code is now there to implement ALTER TABLE ADD CONSTRAINT and ALTER TABLE ADD COLUMN with a default value. I didn't actually teach ALTER TABLE to call it, but it wouldn't be much work.
1999-10-04 01:55:40 +02:00
Fix performance problems with pg_index lookups (see, for example, discussion of 5/19/00). pg_index is now searched for indexes of a relation using an indexscan. Moreover, this is done once and cached in the relcache entry for the relation, in the form of a list of OIDs for the indexes. This list is used by the parser and executor to drive lookups in the pg_index syscache when they want to know the properties of the indexes. Net result: index information will be fully cached for repetitive operations such as inserts.
2000-06-17 23:49:04 +02:00
/*
* Routines to compute/retrieve additional cached information
*/
extern List *RelationGetIndexList(Relation relation);
Solve the problem of OID collisions by probing for duplicate OIDs whenever we generate a new OID. This prevents occasional duplicate-OID errors that can otherwise occur once the OID counter has wrapped around. Duplicate relfilenode values are also checked for when creating new physical files. Per my recent proposal.
2005-08-12 03:36:05 +02:00
extern Oid RelationGetOidIndex(Relation relation);
Replace functional-index facility with expressional indexes. Any column of an index can now be a computed expression instead of a simple variable. Restrictions on expressions are the same as for predicates (only immutable functions, no sub-selects). This fixes problems recently introduced with inlining SQL functions, because the inlining transformation is applied to both expression trees so the planner can still match them up. Along the way, improve efficiency of handling index predicates (both predicates and index expressions are now cached by the relcache) and fix 7.3 oversight that didn't record dependencies of predicate expressions.
2003-05-28 18:04:02 +02:00
extern List *RelationGetIndexExpressions(Relation relation);
extern List *RelationGetIndexPredicate(Relation relation);
HOT updates. When we update a tuple without changing any of its indexed columns, and the new version can be stored on the same heap page, we no longer generate extra index entries for the new version. Instead, index searches follow the HOT-chain links to ensure they find the correct tuple version. In addition, this patch introduces the ability to "prune" dead tuples on a per-page basis, without having to do a complete VACUUM pass to recover space. VACUUM is still needed to clean up dead index entries, however. Pavan Deolasee, with help from a bunch of other people.
2007-09-20 19:56:33 +02:00
extern Bitmapset *RelationGetIndexAttrBitmap(Relation relation);
Fix performance problems with pg_index lookups (see, for example, discussion of 5/19/00). pg_index is now searched for indexes of a relation using an indexscan. Moreover, this is done once and cached in the relcache entry for the relation, in the form of a list of OIDs for the indexes. This list is used by the parser and executor to drive lookups in the pg_index syscache when they want to know the properties of the indexes. Net result: index information will be fully cached for repetitive operations such as inserts.
2000-06-17 23:49:04 +02:00
Solve the problem of OID collisions by probing for duplicate OIDs whenever we generate a new OID. This prevents occasional duplicate-OID errors that can otherwise occur once the OID counter has wrapped around. Duplicate relfilenode values are also checked for when creating new physical files. Per my recent proposal.
2005-08-12 03:36:05 +02:00
extern void RelationSetIndexList(Relation relation,
Standard pgindent run for 8.1.
2005-10-15 04:49:52 +02:00
List *indexIds, Oid oidIndex);
Repair some REINDEX problems per recent discussions. The relcache is now able to cope with assigning new relfilenode values to nailed-in-cache indexes, so they can be reindexed using the fully crash-safe method. This leaves only shared system indexes as special cases. Remove the 'index deactivation' code, since it provides no useful protection in the shared- index case. Require reindexing of shared indexes to be done in standalone mode, but remove other restrictions on REINDEX. -P (IgnoreSystemIndexes) now prevents using indexes for lookups, but does not disable index updates. It is therefore safe to allow from PGOPTIONS. Upshot: reindexing system catalogs can be done without a standalone backend for all cases except shared catalogs.
2003-09-24 20:54:02 +02:00
Rearrange fmgr.c and relcache so that it's possible to keep FmgrInfo lookup info in the relcache for index access method support functions. This makes a huge difference for dynamically loaded support functions, and should save a few cycles even for built-in ones. Also tweak dfmgr.c so that load_external_function is called only once, not twice, when doing fmgr_info for a dynamically loaded function. All per performance gripe from Teodor Sigaev, 5-Oct-01.
2001-10-07 01:21:45 +02:00
extern void RelationInitIndexAccessInfo(Relation relation);
Toast all the system-table columns that seem to need it. It turns out that giving pg_proc a toast table required solving the same problems we'd have to solve for pg_class --- pg_proc is one of the relations that gets bootstrapped in relcache.c. Solution is to go back at the end of initialization and read in the *real* pg_class row to replace the phony entry created by formrdesc(). This should work as long as there's no need to touch any toasted values during initialization, which seems a reasonable assumption. Although I did not add a toast-table for every single system table with a varlena attribute, I believe that it would work to just do ALTER TABLE pg_class CREATE TOAST TABLE. So anyone who's really intent on having several thousand ACL entries for a rel could do it. NOTE: I didn't force initdb, but you must do one to see the effects of this patch.
2000-08-06 06:40:08 +02:00
/*
* Routines for backend startup
*/
extern void RelationCacheInitialize(void);
extern void RelationCacheInitializePhase2(void);
Further work on connecting the free space map (which is still just a stub) into the rest of the system. Adopt a cleaner approach to preventing deadlock in concurrent heap_updates: allow RelationGetBufferForTuple to select any page of the rel, and put the onus on it to lock both buffers in a consistent order. Remove no-longer-needed isExtend hack from API of ReleaseAndReadBuffer.
2001-06-29 23:08:25 +02:00
/*
* Routine to create a relcache entry for an about-to-be-created relation
*/
extern Relation RelationBuildLocalRelation(const char *relname,
pg_class has a relnamespace column. You can create and access tables in schemas other than the system namespace; however, there's no search path yet, and not all operations work yet on tables outside the system namespace.
2002-03-26 20:17:02 +01:00
Oid relnamespace,
pgindent run on all C files. Java run to follow. initdb/regression tests pass.
2001-10-25 07:50:21 +02:00
TupleDesc tupDesc,
Tablespaces. Alternate database locations are dead, long live tablespaces. There are various things left to do: contrib dbsize and oid2name modules need work, and so does the documentation. Also someone should think about COMMENT ON TABLESPACE and maybe RENAME TABLESPACE. Also initlocation is dead, it just doesn't know it yet. Gavin Sherry and Tom Lane.
2004-06-18 08:14:31 +02:00
Oid relid,
Oid reltablespace,
First phase of project to use fixed OIDs for all system catalogs and indexes. Extend the macros in include/catalog/*.h to carry the info about hand-assigned OIDs, and adjust the genbki script and bootstrap code to make the relations actually get those OIDs. Remove the small number of RelOid_pg_foo macros that we had in favor of a complete set named like the catname.h and indexing.h macros. Next phase will get rid of internal use of names for looking up catalogs and indexes; but this completes the changes forcing an initdb, so it looks like a good place to commit. Along the way, I made the shared relations (pg_database etc) not be 'bootstrap' relations any more, so as to reduce the number of hardwired entries and simplify changing those relations in future. I'm not sure whether they ever really needed to be handled as bootstrap relations, but it seems to work fine to not do so now.
2005-04-14 03:38:22 +02:00
bool shared_relation);
Further work on connecting the free space map (which is still just a stub) into the rest of the system. Adopt a cleaner approach to preventing deadlock in concurrent heap_updates: allow RelationGetBufferForTuple to select any page of the rel, and put the onus on it to lock both buffers in a consistent order. Remove no-longer-needed isExtend hack from API of ReleaseAndReadBuffer.
2001-06-29 23:08:25 +02:00
Reimplement parsing and storage of default expressions and constraint expressions in CREATE TABLE. There is no longer an emasculated expression syntax for these things; it's full a_expr for constraints, and b_expr for defaults (unfortunately the fact that NOT NULL is a part of the column constraint syntax causes a shift/reduce conflict if you try a_expr. Oh well --- at least parenthesized boolean expressions work now). Also, stored expression for a column default is not pre-coerced to the column type; we rely on transformInsertStatement to do that when the default is actually used. This means "f1 datetime default 'now'" behaves the way people usually expect it to. BTW, all the support code is now there to implement ALTER TABLE ADD CONSTRAINT and ALTER TABLE ADD COLUMN with a default value. I didn't actually teach ALTER TABLE to call it, but it wouldn't be much work.
1999-10-04 01:55:40 +02:00
/*
* Routines for flushing/rebuilding relcache entries in various scenarios
*/
Further work on connecting the free space map (which is still just a stub) into the rest of the system. Adopt a cleaner approach to preventing deadlock in concurrent heap_updates: allow RelationGetBufferForTuple to select any page of the rel, and put the onus on it to lock both buffers in a consistent order. Remove no-longer-needed isExtend hack from API of ReleaseAndReadBuffer.
2001-06-29 23:08:25 +02:00
extern void RelationForgetRelation(Oid rid);
Phase 1 of fix for 'SMgrRelation hashtable corrupted' problem. This is the minimum required fix. I want to look next at taking advantage of it by simplifying the message semantics in the shared inval message queue, but that part can be held over for 8.1 if it turns out too ugly.
2005-01-10 21:02:24 +01:00
extern void RelationCacheInvalidateEntry(Oid relationId);
More cleanups of the include files - centralizing to simplify the -I's required to compile
1996-08-28 03:59:28 +02:00
Fix problems seen in parallel regress tests when SI buffer overruns (causing syscache and relcache flushes). Relcache entry rebuild now preserves original tupledesc, rewrite rules, and triggers if possible, so that pointers to these things remain valid --- if these things change while relcache entry has positive refcount, we elog(ERROR) to avoid later crash. Arrange for xact-local rels to be rebuilt when an SI inval message is seen for them, so that they are updated by CommandCounterIncrement the same as regular rels. (This is useful because of Hiroshi's recent changes to process our own SI messages at CommandCounterIncrement time.) This allows simplification of some routines that previously hacked around the lack of an automatic update. catcache now keeps its own copy of tupledesc for its relation, rather than depending on the relcache's copy; this avoids needing to reinitialize catcache during a cache flush, which saves some cycles and eliminates nasty circularity problems that occur if a cache flush happens while trying to initialize a catcache. Eliminate a number of permanent memory leaks that used to happen during catcache or relcache flush; not least of which was that catcache never freed any cached tuples! (Rule parsetree storage is still leaked, however; will fix that separately.) Nothing done yet about code that uses tuples retrieved by SearchSysCache for longer than is safe.
2000-01-31 05:35:57 +01:00
extern void RelationCacheInvalidate(void);
More cleanups of the include files - centralizing to simplify the -I's required to compile
1996-08-28 03:59:28 +02:00
Nested transactions. There is still much left to do, especially on the performance front, but with feature freeze upon us I think it's time to drive a stake in the ground and say that this will be in 7.5. Alvaro Herrera, with some help from Tom Lane.
2004-07-01 02:52:04 +02:00
extern void AtEOXact_RelationCache(bool isCommit);
Restructure subtransaction handling to reduce resource consumption, as per recent discussions. Invent SubTransactionIds that are managed like CommandIds (ie, counter is reset at start of each top transaction), and use these instead of TransactionIds to keep track of subtransaction status in those modules that need it. This means that a subtransaction does not need an XID unless it actually inserts/modifies rows in the database. Accordingly, don't assign it an XID nor take a lock on the XID until it tries to do that. This saves a lot of overhead for subtransactions that are only used for error recovery (eg plpgsql exceptions). Also, arrange to release a subtransaction's XID lock as soon as the subtransaction exits, in both the commit and abort cases. This avoids holding many unique locks after a long series of subtransactions. The price is some additional overhead in XactLockTableWait, but that seems acceptable. Finally, restructure the state machine in xact.c to have a more orthogonal set of states for subtransactions.
2004-09-16 18:58:44 +02:00
extern void AtEOSubXact_RelationCache(bool isCommit, SubTransactionId mySubid,
Standard pgindent run for 8.1.
2005-10-15 04:49:52 +02:00
SubTransactionId parentSubid);
Modify RelationFlushRelation so that if the relcache entry has positive refcount, it is rebuilt from pg_class data. This ensures that relcache entries will track changes made by other backends. Formerly, a shared inval report would just be ignored if it happened to arrive while the relcache entry was in use. Also, fix relcache to reset ref counts to zero during transaction abort. Finally, change LockRelation() so that it checks for shared inval reports after obtaining the lock. In this way, once any kind of lock has been obtained on a rel, we can trust the relcache entry to be up-to-date.
1999-09-04 20:42:15 +02:00
Teach CLUSTER to skip writing WAL if not needed (ie, not using archiving) --- Simon. Also, code review and cleanup for the previous COPY-no-WAL patches --- Tom.
2007-03-29 02:15:39 +02:00
extern void RelationCacheMarkNewRelfilenode(Relation rel);
A bunch of changes aimed at reducing backend startup time... Improve 'pg_internal.init' relcache entry preload mechanism so that it is safe to use for all system catalogs, and arrange to preload a realistic set of system-catalog entries instead of only the three nailed-in-cache indexes that were formerly loaded this way. Fix mechanism for deleting out-of-date pg_internal.init files: this must be synchronized with transaction commit, not just done at random times within transactions. Drive it off relcache invalidation mechanism so that no special-case tests are needed. Cache additional information in relcache entries for indexes (their pg_index tuples and index-operator OIDs) to eliminate repeated lookups. Also cache index opclass info at the per-opclass level to avoid repeated lookups during relcache load. Generalize 'systable scan' utilities originally developed by Hiroshi, move them into genam.c, use in a number of places where there was formerly ugly code for choosing either heap or index scan. In particular this allows simplification of the logic that prevents infinite recursion between syscache and relcache during startup: we can easily switch to heapscans in relcache.c when and where needed to avoid recursion, so IndexScanOK becomes simpler and does not need any expensive initialization. Eliminate useless opening of a heapscan data structure while doing an indexscan (this saves an mdnblocks call and thus at least one kernel call).
2002-02-19 21:11:20 +01:00
/*
* Routines to help manage rebuilding of relcache init file
*/
extern bool RelationIdIsInInitFile(Oid relationId);
extern void RelationCacheInitFileInvalidate(bool beforeSend);
Fix recently-identified PITR recovery hazard: the base backup could contain stale relcache init files (pg_internal.init), and there is no mechanism for updating them during WAL replay. Easiest solution is just to delete the init files at conclusion of startup, and let the first backend started in each database take care of rebuilding the init file. Simon Riggs and Tom Lane. Back-patched to 8.1. Arguably this should be fixed in 8.0 too, but it would require significantly more code since 8.0 has no handy startup-time scan of pg_database to piggyback on. Manual solution of the problem is possible in 8.0 (just delete the pg_internal.init files before starting WAL replay), so that may be a sufficient answer.
2006-11-06 00:40:31 +01:00
extern void RelationCacheInitFileRemove(const char *dbPath);
Put external declarations into header files.
2000-11-21 22:16:06 +01:00
A bunch of changes aimed at reducing backend startup time... Improve 'pg_internal.init' relcache entry preload mechanism so that it is safe to use for all system catalogs, and arrange to preload a realistic set of system-catalog entries instead of only the three nailed-in-cache indexes that were formerly loaded this way. Fix mechanism for deleting out-of-date pg_internal.init files: this must be synchronized with transaction commit, not just done at random times within transactions. Drive it off relcache invalidation mechanism so that no special-case tests are needed. Cache additional information in relcache entries for indexes (their pg_index tuples and index-operator OIDs) to eliminate repeated lookups. Also cache index opclass info at the per-opclass level to avoid repeated lookups during relcache load. Generalize 'systable scan' utilities originally developed by Hiroshi, move them into genam.c, use in a number of places where there was formerly ugly code for choosing either heap or index scan. In particular this allows simplification of the logic that prevents infinite recursion between syscache and relcache during startup: we can easily switch to heapscans in relcache.c when and where needed to avoid recursion, so IndexScanOK becomes simpler and does not need any expensive initialization. Eliminate useless opening of a heapscan data structure while doing an indexscan (this saves an mdnblocks call and thus at least one kernel call).
2002-02-19 21:11:20 +01:00
/* should be used only by relcache.c and catcache.c */
extern bool criticalRelcachesBuilt;
Another pgindent run. Fixes enum indenting, and improves #endif spacing. Also adds space for one-line comments.
2001-10-28 07:26:15 +01:00
New pgindent run with fixes suggested by Tom. Patch manually reviewed, initdb/regression tests pass.
2001-11-05 18:46:40 +01:00
#endif /* RELCACHE_H */