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postgres/src/include/utils/relcache.h
Tomas Vondra e3fcca0d0d Revert changes in HOT handling of BRIN indexes
This reverts commits 5753d4ee32 and fe60b67250 that modified HOT to
ignore BRIN indexes. The commit message for 5753d4ee32 claims that:

    When determining whether an index update may be skipped by using
    HOT, we can ignore attributes indexed only by BRIN indexes. There
    are no index pointers to individual tuples in BRIN, and the page
    range summary will be updated anyway as it relies on visibility
    info.

This is partially incorrect - it's true BRIN indexes don't point to
individual tuples, so HOT chains are not an issue, but the visibitlity
info is not sufficient to keep the index up to date. This can easily
result in corrupted indexes, as demonstrated in the hackers thread.

This does not mean relaxing the HOT restrictions for BRIN is a lost
cause, but it needs to handle the two aspects (allowing HOT chains and
updating the page range summaries) as separate. But that requires a
major changes, and it's too late for that in the current dev cycle.

Reported-by: Tomas Vondra
Discussion: https://postgr.es/m/05ebcb44-f383-86e3-4f31-0a97a55634cf@enterprisedb.com
2022-06-16 15:02:49 +02:00

154 lines
4.7 KiB
C

/*-------------------------------------------------------------------------
*
* relcache.h
* Relation descriptor cache definitions.
*
*
* Portions Copyright (c) 1996-2022, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* src/include/utils/relcache.h
*
*-------------------------------------------------------------------------
*/
#ifndef RELCACHE_H
#define RELCACHE_H
#include "access/tupdesc.h"
#include "nodes/bitmapset.h"
/*
* Name of relcache init file(s), used to speed up backend startup
*/
#define RELCACHE_INIT_FILENAME "pg_internal.init"
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;
/*
* Routines to open (lookup) and close a relcache entry
*/
extern Relation RelationIdGetRelation(Oid relationId);
extern void RelationClose(Relation relation);
/*
* Routines to compute/retrieve additional cached information
*/
extern List *RelationGetFKeyList(Relation relation);
extern List *RelationGetIndexList(Relation relation);
extern List *RelationGetStatExtList(Relation relation);
extern Oid RelationGetPrimaryKeyIndex(Relation relation);
extern Oid RelationGetReplicaIndex(Relation relation);
extern List *RelationGetIndexExpressions(Relation relation);
extern List *RelationGetDummyIndexExpressions(Relation relation);
extern List *RelationGetIndexPredicate(Relation relation);
extern Datum *RelationGetIndexRawAttOptions(Relation relation);
extern bytea **RelationGetIndexAttOptions(Relation relation, bool copy);
typedef enum IndexAttrBitmapKind
{
INDEX_ATTR_BITMAP_ALL,
INDEX_ATTR_BITMAP_KEY,
INDEX_ATTR_BITMAP_PRIMARY_KEY,
INDEX_ATTR_BITMAP_IDENTITY_KEY
} IndexAttrBitmapKind;
extern Bitmapset *RelationGetIndexAttrBitmap(Relation relation,
IndexAttrBitmapKind attrKind);
extern Bitmapset *RelationGetIdentityKeyBitmap(Relation relation);
extern void RelationGetExclusionInfo(Relation indexRelation,
Oid **operators,
Oid **procs,
uint16 **strategies);
extern void RelationInitIndexAccessInfo(Relation relation);
/* caller must include pg_publication.h */
struct PublicationDesc;
extern void RelationBuildPublicationDesc(Relation relation,
struct PublicationDesc *pubdesc);
extern void RelationInitTableAccessMethod(Relation relation);
/*
* Routines to support ereport() reports of relation-related errors
*/
extern int errtable(Relation rel);
extern int errtablecol(Relation rel, int attnum);
extern int errtablecolname(Relation rel, const char *colname);
extern int errtableconstraint(Relation rel, const char *conname);
/*
* Routines for backend startup
*/
extern void RelationCacheInitialize(void);
extern void RelationCacheInitializePhase2(void);
extern void RelationCacheInitializePhase3(void);
/*
* Routine to create a relcache entry for an about-to-be-created relation
*/
extern Relation RelationBuildLocalRelation(const char *relname,
Oid relnamespace,
TupleDesc tupDesc,
Oid relid,
Oid accessmtd,
Oid relfilenode,
Oid reltablespace,
bool shared_relation,
bool mapped_relation,
char relpersistence,
char relkind);
/*
* Routines to manage assignment of new relfilenode to a relation
*/
extern void RelationSetNewRelfilenode(Relation relation, char persistence);
extern void RelationAssumeNewRelfilenode(Relation relation);
/*
* Routines for flushing/rebuilding relcache entries in various scenarios
*/
extern void RelationForgetRelation(Oid rid);
extern void RelationCacheInvalidateEntry(Oid relationId);
extern void RelationCacheInvalidate(bool debug_discard);
extern void RelationCloseSmgrByOid(Oid relationId);
#ifdef USE_ASSERT_CHECKING
extern void AssertPendingSyncs_RelationCache(void);
#else
#define AssertPendingSyncs_RelationCache() do {} while (0)
#endif
extern void AtEOXact_RelationCache(bool isCommit);
extern void AtEOSubXact_RelationCache(bool isCommit, SubTransactionId mySubid,
SubTransactionId parentSubid);
/*
* Routines to help manage rebuilding of relcache init files
*/
extern bool RelationIdIsInInitFile(Oid relationId);
extern void RelationCacheInitFilePreInvalidate(void);
extern void RelationCacheInitFilePostInvalidate(void);
extern void RelationCacheInitFileRemove(void);
/* should be used only by relcache.c and catcache.c */
extern PGDLLIMPORT bool criticalRelcachesBuilt;
/* should be used only by relcache.c and postinit.c */
extern PGDLLIMPORT bool criticalSharedRelcachesBuilt;
#endif /* RELCACHE_H */