rel.h 6.46 KiB
/*-------------------------------------------------------------------------
*
* rel.h
* POSTGRES relation descriptor (a/k/a relcache entry) definitions.
*
*
* Portions Copyright (c) 1996-2000, PostgreSQL, Inc
* Portions Copyright (c) 1994, Regents of the University of California
*
* $Id: rel.h,v 1.43 2000/12/23 19:55:16 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#ifndef REL_H
#define REL_H
#include "access/strat.h"
#include "access/tupdesc.h"
#include "catalog/pg_am.h"
#include "catalog/pg_class.h"
#include "rewrite/prs2lock.h"
#include "storage/relfilenode.h"
#include "storage/fd.h"
/* added to prevent circular dependency. bjm 1999/11/15 */
extern char *get_temp_rel_by_physicalname(const char *relname);
/*
* LockRelId and LockInfo really belong to lmgr.h, but it's more convenient
* to declare them here so we can have a LockInfoData field in a Relation.
*/
typedef struct LockRelId
{
Oid relId; /* a relation identifier */
Oid dbId; /* a database identifier */
} LockRelId;
typedef struct LockInfoData
{
LockRelId lockRelId;
} LockInfoData;
typedef LockInfoData *LockInfo;
/*
* Likewise, this struct really belongs to trigger.h, but for convenience
* we put it here.
*/
typedef struct Trigger
{
Oid tgoid;
char *tgname;
Oid tgfoid;
FmgrInfo tgfunc;
int16 tgtype;
bool tgenabled;
bool tgisconstraint;
bool tgdeferrable;
bool tginitdeferred;
int16 tgnargs;
int16 tgattr[FUNC_MAX_ARGS];
char **tgargs;
} Trigger;
typedef struct TriggerDesc
{
/* index data to identify which triggers are which */
uint16 n_before_statement[4]; uint16 n_before_row[4];
uint16 n_after_row[4];
uint16 n_after_statement[4];
Trigger **tg_before_statement[4];
Trigger **tg_before_row[4];
Trigger **tg_after_row[4];
Trigger **tg_after_statement[4];
/* the actual array of triggers is here */
Trigger *triggers;
int numtriggers;
} TriggerDesc;
/*
* Here are the contents of a relation cache entry.
*/
typedef struct RelationData
{
File rd_fd; /* open file descriptor, or -1 if none */
RelFileNode rd_node; /* relation file node */
int rd_nblocks; /* number of blocks in rel */
uint16 rd_refcnt; /* reference count */
bool rd_myxactonly; /* rel uses the local buffer mgr */
bool rd_isnailed; /* rel is nailed in cache */
bool rd_indexfound; /* true if rd_indexlist is valid */
bool rd_uniqueindex; /* true if rel is a UNIQUE index */
Form_pg_am rd_am; /* AM tuple */
Form_pg_class rd_rel; /* RELATION tuple */
Oid rd_id; /* relation's object id */
List *rd_indexlist; /* list of OIDs of indexes on relation */
LockInfoData rd_lockInfo; /* lock mgr's info for locking relation */
TupleDesc rd_att; /* tuple descriptor */
RuleLock *rd_rules; /* rewrite rules */
MemoryContext rd_rulescxt; /* private memory cxt for rd_rules, if any */
IndexStrategy rd_istrat; /* info needed if rel is an index */
RegProcedure *rd_support;
TriggerDesc *trigdesc; /* Trigger info, or NULL if rel has none */
} RelationData;
typedef 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;
/*
* RelationIsValid
* True iff relation descriptor is valid.
*/
#define RelationIsValid(relation) PointerIsValid(relation)
#define InvalidRelation ((Relation) NULL)
/*
* RelationHasReferenceCountZero
* True iff relation reference count is zero.
*
* Note:
* Assumes relation descriptor is valid.
*/
#define RelationHasReferenceCountZero(relation) \
((bool)((relation)->rd_refcnt == 0))
/* * RelationSetReferenceCount
* Sets relation reference count.
*/
#define RelationSetReferenceCount(relation,count) \
((relation)->rd_refcnt = (count))
/*
* RelationIncrementReferenceCount
* Increments relation reference count.
*/
#define RelationIncrementReferenceCount(relation) \
((relation)->rd_refcnt += 1)
/*
* RelationDecrementReferenceCount
* Decrements relation reference count.
*/
#define RelationDecrementReferenceCount(relation) \
(AssertMacro((relation)->rd_refcnt > 0), \
(relation)->rd_refcnt -= 1)
/*
* RelationGetForm
* Returns pg_class tuple for a relation.
*
* Note:
* Assumes relation descriptor is valid.
*/
#define RelationGetForm(relation) ((relation)->rd_rel)
/*
* RelationGetRelid
*
* returns the OID of the relation
*/
#define RelationGetRelid(relation) ((relation)->rd_id)
/*
* RelationGetFile
*
* Returns the open file descriptor for the rel
*/
#define RelationGetFile(relation) ((relation)->rd_fd)
/*
* RelationGetRelationName
*
* Returns the relation's logical name (as seen by the user).
*
* If the rel is a temp rel, the temp name will be returned. Therefore,
* this name is not unique. But it is the name to use in heap_openr(),
* for example.
*/
#define RelationGetRelationName(relation) \
(\
(strncmp(RelationGetPhysicalRelationName(relation), \
"pg_temp.", 8) != 0) \
? \
RelationGetPhysicalRelationName(relation) \
: \
get_temp_rel_by_physicalname( \
RelationGetPhysicalRelationName(relation)) \
)
/*
* RelationGetPhysicalRelationName
*
* Returns the rel's physical name, ie, the name appearing in pg_class.
* * While this name is unique across all rels in the database, it is not
* necessarily useful for accessing the rel, since a temp table of the
* same name might mask the rel. It is useful mainly for determining if
* the rel is a shared system rel or not.
*
* The macro is rather unfortunately named, since the pg_class name no longer
* has anything to do with the file name used for physical storage of the rel.
*/
#define RelationGetPhysicalRelationName(relation) \
(NameStr((relation)->rd_rel->relname))
/*
* RelationGetNumberOfAttributes
*
* Returns the number of attributes.
*/
#define RelationGetNumberOfAttributes(relation) ((relation)->rd_rel->relnatts)
/*
* RelationGetDescr
* Returns tuple descriptor for a relation.
*/
#define RelationGetDescr(relation) ((relation)->rd_att)
/*
* RelationGetIndexStrategy
* Returns index strategy for a relation.
*
* Note:
* Assumes relation descriptor is valid.
* Assumes relation descriptor is for an index relation.
*/
#define RelationGetIndexStrategy(relation) ((relation)->rd_istrat)
/*
* Routines in utils/cache/rel.c
*/
extern void RelationSetIndexSupport(Relation relation,
IndexStrategy strategy,
RegProcedure *support);
#endif /* REL_H */