1 /*-------------------------------------------------------------------------
4 * POSTGRES relation descriptor (a/k/a relcache entry) definitions.
7 * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
8 * Portions Copyright (c) 1994, Regents of the University of California
10 * $Id: rel.h,v 1.70 2003/11/12 21:15:59 tgl Exp $
12 *-------------------------------------------------------------------------
17 #include "access/tupdesc.h"
18 #include "catalog/pg_am.h"
19 #include "catalog/pg_class.h"
20 #include "catalog/pg_index.h"
21 #include "rewrite/prs2lock.h"
22 #include "storage/block.h"
23 #include "storage/fd.h"
24 #include "storage/relfilenode.h"
28 * LockRelId and LockInfo really belong to lmgr.h, but it's more convenient
29 * to declare them here so we can have a LockInfoData field in a Relation.
32 typedef struct LockRelId
34 Oid relId; /* a relation identifier */
35 Oid dbId; /* a database identifier */
38 typedef struct LockInfoData
43 typedef LockInfoData *LockInfo;
46 * Likewise, this struct really belongs to trigger.h, but for convenience
49 typedef struct Trigger
51 Oid tgoid; /* OID of trigger (pg_trigger row) */
52 /* Remaining fields are copied from pg_trigger, see pg_trigger.h */
62 int16 tgattr[FUNC_MAX_ARGS];
66 typedef struct TriggerDesc
69 * Index data to identify which triggers are which. Since each
70 * trigger can appear in more than one class, for each class we
71 * provide a list of integer indexes into the triggers array.
73 #define TRIGGER_NUM_EVENT_CLASSES 3
75 uint16 n_before_statement[TRIGGER_NUM_EVENT_CLASSES];
76 uint16 n_before_row[TRIGGER_NUM_EVENT_CLASSES];
77 uint16 n_after_row[TRIGGER_NUM_EVENT_CLASSES];
78 uint16 n_after_statement[TRIGGER_NUM_EVENT_CLASSES];
79 int *tg_before_statement[TRIGGER_NUM_EVENT_CLASSES];
80 int *tg_before_row[TRIGGER_NUM_EVENT_CLASSES];
81 int *tg_after_row[TRIGGER_NUM_EVENT_CLASSES];
82 int *tg_after_statement[TRIGGER_NUM_EVENT_CLASSES];
84 /* The actual array of triggers is here */
91 * Same for the statistics collector data in Relation and scan data.
93 typedef struct PgStat_Info
97 bool heap_scan_counted;
98 bool index_scan_counted;
102 * Here are the contents of a relation cache entry.
105 typedef struct RelationData
107 File rd_fd; /* open file descriptor, or -1 if none */
108 RelFileNode rd_node; /* file node (physical identifier) */
109 BlockNumber rd_nblocks; /* number of blocks in rel */
110 BlockNumber rd_targblock; /* current insertion target block, or
111 * InvalidBlockNumber */
112 int rd_refcnt; /* reference count */
113 bool rd_isnew; /* rel was created in current xact */
116 * NOTE: rd_isnew should be relied on only for optimization purposes;
117 * it is possible for new-ness to be "forgotten" (eg, after CLUSTER).
119 bool rd_istemp; /* rel uses the local buffer mgr */
120 char rd_isnailed; /* rel is nailed in cache: 0 = no, 1 = yes,
121 * 2 = yes but possibly invalid */
122 char rd_indexvalid; /* state of rd_indexlist: 0 = not valid,
123 * 1 = valid, 2 = temporarily forced */
124 Form_pg_class rd_rel; /* RELATION tuple */
125 TupleDesc rd_att; /* tuple descriptor */
126 Oid rd_id; /* relation's object id */
127 List *rd_indexlist; /* list of OIDs of indexes on relation */
128 LockInfoData rd_lockInfo; /* lock mgr's info for locking relation */
129 RuleLock *rd_rules; /* rewrite rules */
130 MemoryContext rd_rulescxt; /* private memory cxt for rd_rules, if any */
131 TriggerDesc *trigdesc; /* Trigger info, or NULL if rel has none */
133 /* These are non-NULL only for an index relation: */
134 Form_pg_index rd_index; /* pg_index tuple describing this index */
135 struct HeapTupleData *rd_indextuple; /* all of pg_index tuple */
136 /* "struct HeapTupleData *" avoids need to include htup.h here */
137 Form_pg_am rd_am; /* pg_am tuple for index's AM */
140 * index access support info (used only for an index relation)
142 * Note: only default operators and support procs for each opclass are
143 * cached, namely those with subtype zero. The arrays are indexed by
144 * strategy or support number, which is a sufficient identifier given
147 MemoryContext rd_indexcxt; /* private memory cxt for this stuff */
148 Oid *rd_operator; /* OIDs of index operators */
149 RegProcedure *rd_support; /* OIDs of support procedures */
150 struct FmgrInfo *rd_supportinfo; /* lookup info for support
152 /* "struct FmgrInfo" avoids need to include fmgr.h here */
153 List *rd_indexprs; /* index expression trees, if any */
154 List *rd_indpred; /* index predicate tree, if any */
156 /* statistics collection area */
157 PgStat_Info pgstat_info;
160 typedef RelationData *Relation;
164 * RelationPtr is used in the executor to support index scans
165 * where we have to keep track of several index relations in an
166 * array. -cim 9/10/89
169 typedef Relation *RelationPtr;
174 * True iff relation descriptor is valid.
176 #define RelationIsValid(relation) PointerIsValid(relation)
178 #define InvalidRelation ((Relation) NULL)
181 * RelationHasReferenceCountZero
182 * True iff relation reference count is zero.
185 * Assumes relation descriptor is valid.
187 #define RelationHasReferenceCountZero(relation) \
188 ((bool)((relation)->rd_refcnt == 0))
191 * RelationSetReferenceCount
192 * Sets relation reference count.
194 #define RelationSetReferenceCount(relation,count) \
195 ((relation)->rd_refcnt = (count))
198 * RelationIncrementReferenceCount
199 * Increments relation reference count.
201 #define RelationIncrementReferenceCount(relation) \
202 ((relation)->rd_refcnt += 1)
205 * RelationDecrementReferenceCount
206 * Decrements relation reference count.
208 #define RelationDecrementReferenceCount(relation) \
209 (AssertMacro((relation)->rd_refcnt > 0), \
210 (relation)->rd_refcnt -= 1)
214 * Returns pg_class tuple for a relation.
217 * Assumes relation descriptor is valid.
219 #define RelationGetForm(relation) ((relation)->rd_rel)
224 * returns the OID of the relation
226 #define RelationGetRelid(relation) ((relation)->rd_id)
231 * Returns the open file descriptor for the rel
233 #define RelationGetFile(relation) ((relation)->rd_fd)
236 * RelationGetNumberOfAttributes
238 * Returns the number of attributes.
240 #define RelationGetNumberOfAttributes(relation) ((relation)->rd_rel->relnatts)
244 * Returns tuple descriptor for a relation.
246 #define RelationGetDescr(relation) ((relation)->rd_att)
249 * RelationGetRelationName
251 * Returns the rel's name.
253 * Note that the name is only unique within the containing namespace.
255 #define RelationGetRelationName(relation) \
256 (NameStr((relation)->rd_rel->relname))
259 * RelationGetNamespace
261 * Returns the rel's namespace OID.
263 #define RelationGetNamespace(relation) \
264 ((relation)->rd_rel->relnamespace)