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f905d65ee3
a separate statement (though it can still be invoked as part of VACUUM, too). pg_statistic redesigned to be more flexible about what statistics are stored. ANALYZE now collects a list of several of the most common values, not just one, plus a histogram (not just the min and max values). Random sampling is used to make the process reasonably fast even on very large tables. The number of values and histogram bins collected is now user-settable via an ALTER TABLE command. There is more still to do; the new stats are not being used everywhere they could be in the planner. But the remaining changes for this project should be localized, and the behavior is already better than before. A not-very-related change is that sorting now makes use of btree comparison routines if it can find one, rather than invoking '<' twice.
80 lines
2.1 KiB
C
80 lines
2.1 KiB
C
/*-------------------------------------------------------------------------
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*
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* syscache.h
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* System catalog cache definitions.
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*
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* See also lsyscache.h, which provides convenience routines for
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* common cache-lookup operations.
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*
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* Portions Copyright (c) 1996-2001, 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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* $Id: syscache.h,v 1.30 2001/05/07 00:43:26 tgl Exp $
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*
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*-------------------------------------------------------------------------
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*/
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#ifndef SYSCACHE_H
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#define SYSCACHE_H
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#include "access/htup.h"
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/*
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* Declarations for util/syscache.c.
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*
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* SysCache identifiers.
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*
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* The order of these must match the order
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* they are entered into the structure cacheinfo[] in syscache.c.
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* Keep them in alphabetical order.
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*/
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#define AGGNAME 0
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#define AMNAME 1
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#define AMOPOPID 2
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#define AMOPSTRATEGY 3
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#define ATTNAME 4
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#define ATTNUM 5
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#define CLADEFTYPE 6
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#define CLANAME 7
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#define GRONAME 8
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#define GROSYSID 9
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#define INDEXRELID 10
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#define INHRELID 11
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#define LANGNAME 12
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#define LANGOID 13
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#define LISTENREL 14
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#define OPERNAME 15
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#define OPEROID 16
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#define PROCNAME 17
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#define PROCOID 18
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#define RELNAME 19
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#define RELOID 20
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#define RULENAME 21
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#define RULEOID 22
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#define SHADOWNAME 23
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#define SHADOWSYSID 24
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#define STATRELATT 25
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#define TYPENAME 26
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#define TYPEOID 27
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extern void InitCatalogCache(void);
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extern HeapTuple SearchSysCache(int cacheId,
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Datum key1, Datum key2, Datum key3, Datum key4);
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extern void ReleaseSysCache(HeapTuple tuple);
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/* convenience routines */
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extern HeapTuple SearchSysCacheCopy(int cacheId,
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Datum key1, Datum key2, Datum key3, Datum key4);
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extern Oid GetSysCacheOid(int cacheId,
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Datum key1, Datum key2, Datum key3, Datum key4);
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/* macro for just probing for existence of a tuple via the syscache */
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#define SearchSysCacheExists(c,k1,k2,k3,k4) \
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OidIsValid(GetSysCacheOid(c,k1,k2,k3,k4))
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extern Datum SysCacheGetAttr(int cacheId, HeapTuple tup,
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AttrNumber attributeNumber, bool *isNull);
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#endif /* SYSCACHE_H */
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