1 /*-------------------------------------------------------------------------
4 * POSTGRES relation descriptor (a/k/a relcache entry) definitions.
7 * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
8 * Portions Copyright (c) 1994, Regents of the University of California
10 * $Id: rel.h,v 1.56 2002/02/19 20:11:19 tgl Exp $
12 *-------------------------------------------------------------------------
17 #include "access/strat.h"
18 #include "access/tupdesc.h"
19 #include "catalog/pg_am.h"
20 #include "catalog/pg_class.h"
21 #include "catalog/pg_index.h"
22 #include "rewrite/prs2lock.h"
23 #include "storage/block.h"
24 #include "storage/fd.h"
25 #include "storage/relfilenode.h"
29 * LockRelId and LockInfo really belong to lmgr.h, but it's more convenient
30 * to declare them here so we can have a LockInfoData field in a Relation.
33 typedef struct LockRelId
35 Oid relId; /* a relation identifier */
36 Oid dbId; /* a database identifier */
39 typedef struct LockInfoData
44 typedef LockInfoData *LockInfo;
47 * Likewise, this struct really belongs to trigger.h, but for convenience
50 typedef struct Trigger
61 int16 tgattr[FUNC_MAX_ARGS];
65 typedef struct TriggerDesc
68 * Index data to identify which triggers are which. Since each
69 * trigger can appear in more than one class, for each class we
70 * provide a list of integer indexes into the triggers array.
72 #define TRIGGER_NUM_EVENT_CLASSES 4
74 uint16 n_before_statement[TRIGGER_NUM_EVENT_CLASSES];
75 uint16 n_before_row[TRIGGER_NUM_EVENT_CLASSES];
76 uint16 n_after_row[TRIGGER_NUM_EVENT_CLASSES];
77 uint16 n_after_statement[TRIGGER_NUM_EVENT_CLASSES];
78 int *tg_before_statement[TRIGGER_NUM_EVENT_CLASSES];
79 int *tg_before_row[TRIGGER_NUM_EVENT_CLASSES];
80 int *tg_after_row[TRIGGER_NUM_EVENT_CLASSES];
81 int *tg_after_statement[TRIGGER_NUM_EVENT_CLASSES];
83 /* The actual array of triggers is here */
90 * 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_myxactonly; /* rel uses the local buffer mgr */
114 bool rd_isnailed; /* rel is nailed in cache */
115 bool rd_indexfound; /* true if rd_indexlist is valid */
116 bool rd_uniqueindex; /* true if rel is a UNIQUE index */
117 Form_pg_class rd_rel; /* RELATION tuple */
118 TupleDesc rd_att; /* tuple descriptor */
119 Oid rd_id; /* relation's object id */
120 List *rd_indexlist; /* list of OIDs of indexes on relation */
121 LockInfoData rd_lockInfo; /* lock mgr's info for locking relation */
122 RuleLock *rd_rules; /* rewrite rules */
123 MemoryContext rd_rulescxt; /* private memory cxt for rd_rules, if any */
124 TriggerDesc *trigdesc; /* Trigger info, or NULL if rel has none */
126 /* These are non-NULL only for an index relation: */
127 Form_pg_index rd_index; /* pg_index tuple describing this index */
128 Form_pg_am rd_am; /* pg_am tuple for index's AM */
130 /* index access support info (used only for an index relation) */
131 MemoryContext rd_indexcxt; /* private memory cxt for this stuff */
132 IndexStrategy rd_istrat; /* operator strategy map */
133 Oid *rd_operator; /* OIDs of index operators */
134 RegProcedure *rd_support; /* OIDs of support procedures */
135 struct FmgrInfo *rd_supportinfo; /* lookup info for support
137 /* "struct FmgrInfo" avoids need to include fmgr.h here */
139 /* statistics collection area */
140 PgStat_Info pgstat_info;
143 typedef RelationData *Relation;
147 * RelationPtr is used in the executor to support index scans
148 * where we have to keep track of several index relations in an
149 * array. -cim 9/10/89
152 typedef Relation *RelationPtr;
157 * True iff relation descriptor is valid.
159 #define RelationIsValid(relation) PointerIsValid(relation)
161 #define InvalidRelation ((Relation) NULL)
164 * RelationHasReferenceCountZero
165 * True iff relation reference count is zero.
168 * Assumes relation descriptor is valid.
170 #define RelationHasReferenceCountZero(relation) \
171 ((bool)((relation)->rd_refcnt == 0))
174 * RelationSetReferenceCount
175 * Sets relation reference count.
177 #define RelationSetReferenceCount(relation,count) \
178 ((relation)->rd_refcnt = (count))
181 * RelationIncrementReferenceCount
182 * Increments relation reference count.
184 #define RelationIncrementReferenceCount(relation) \
185 ((relation)->rd_refcnt += 1)
188 * RelationDecrementReferenceCount
189 * Decrements relation reference count.
191 #define RelationDecrementReferenceCount(relation) \
192 (AssertMacro((relation)->rd_refcnt > 0), \
193 (relation)->rd_refcnt -= 1)
197 * Returns pg_class tuple for a relation.
200 * Assumes relation descriptor is valid.
202 #define RelationGetForm(relation) ((relation)->rd_rel)
207 * returns the OID of the relation
209 #define RelationGetRelid(relation) ((relation)->rd_id)
214 * Returns the open file descriptor for the rel
216 #define RelationGetFile(relation) ((relation)->rd_fd)
219 * RelationGetNumberOfAttributes
221 * Returns the number of attributes.
223 #define RelationGetNumberOfAttributes(relation) ((relation)->rd_rel->relnatts)
227 * Returns tuple descriptor for a relation.
229 #define RelationGetDescr(relation) ((relation)->rd_att)
232 * RelationGetIndexStrategy
233 * Returns index strategy for a relation.
236 * Assumes relation descriptor is valid.
237 * Assumes relation descriptor is for an index relation.
239 #define RelationGetIndexStrategy(relation) ((relation)->rd_istrat)
242 * Handle temp relations
244 #define PG_TEMP_REL_PREFIX "pg_temp"
245 #define PG_TEMP_REL_PREFIX_LEN 7
247 #define is_temp_relname(relname) \
248 (strncmp(relname, PG_TEMP_REL_PREFIX, PG_TEMP_REL_PREFIX_LEN) == 0)
251 * RelationGetPhysicalRelationName
253 * Returns the rel's physical name, ie, the name appearing in pg_class.
255 * While this name is unique across all rels in the database, it is not
256 * necessarily useful for accessing the rel, since a temp table of the
257 * same name might mask the rel. It is useful mainly for determining if
258 * the rel is a shared system rel or not.
260 * The macro is rather unfortunately named, since the pg_class name no longer
261 * has anything to do with the file name used for physical storage of the rel.
263 #define RelationGetPhysicalRelationName(relation) \
264 (NameStr((relation)->rd_rel->relname))
267 * RelationGetRelationName
269 * Returns the relation's logical name (as seen by the user).
271 * If the rel is a temp rel, the temp name will be returned. Therefore,
272 * this name is not unique. But it is the name to use in heap_openr(),
275 #define RelationGetRelationName(relation) \
277 is_temp_relname(RelationGetPhysicalRelationName(relation)) \
279 get_temp_rel_by_physicalname( \
280 RelationGetPhysicalRelationName(relation)) \
282 RelationGetPhysicalRelationName(relation) \
285 /* added to prevent circular dependency. bjm 1999/11/15 */
286 extern char *get_temp_rel_by_physicalname(const char *relname);