1 /*-------------------------------------------------------------------------
4 * POSTGRES relation descriptor (a/k/a relcache entry) definitions.
7 * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
8 * Portions Copyright (c) 1994, Regents of the University of California
10 * $PostgreSQL: pgsql/src/include/utils/rel.h,v 1.92 2006/10/04 00:30:10 momjian 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"
22 #include "rewrite/prs2lock.h"
23 #include "storage/block.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 */
67 typedef struct TriggerDesc
70 * Index data to identify which triggers are which. Since each trigger
71 * can appear in more than one class, for each class we provide a list of
72 * integer indexes into the triggers array.
74 #define TRIGGER_NUM_EVENT_CLASSES 3
76 uint16 n_before_statement[TRIGGER_NUM_EVENT_CLASSES];
77 uint16 n_before_row[TRIGGER_NUM_EVENT_CLASSES];
78 uint16 n_after_row[TRIGGER_NUM_EVENT_CLASSES];
79 uint16 n_after_statement[TRIGGER_NUM_EVENT_CLASSES];
80 int *tg_before_statement[TRIGGER_NUM_EVENT_CLASSES];
81 int *tg_before_row[TRIGGER_NUM_EVENT_CLASSES];
82 int *tg_after_row[TRIGGER_NUM_EVENT_CLASSES];
83 int *tg_after_statement[TRIGGER_NUM_EVENT_CLASSES];
85 /* The actual array of triggers is here */
92 * Same for the statistics collector data in Relation and scan data.
94 typedef struct PgStat_Info
101 * Cached lookup information for the index access method functions defined
102 * by the pg_am row associated with an index relation.
104 typedef struct RelationAmInfo
107 FmgrInfo ambeginscan;
115 FmgrInfo ambulkdelete;
116 FmgrInfo amvacuumcleanup;
117 FmgrInfo amcostestimate;
123 * Here are the contents of a relation cache entry.
126 typedef struct RelationData
128 RelFileNode rd_node; /* relation physical identifier */
129 /* use "struct" here to avoid needing to include smgr.h: */
130 struct SMgrRelationData *rd_smgr; /* cached file handle, or NULL */
131 BlockNumber rd_targblock; /* current insertion target block, or
132 * InvalidBlockNumber */
133 int rd_refcnt; /* reference count */
134 bool rd_istemp; /* rel uses the local buffer mgr */
135 bool rd_isnailed; /* rel is nailed in cache */
136 bool rd_isvalid; /* relcache entry is valid */
137 char rd_indexvalid; /* state of rd_indexlist: 0 = not valid, 1 =
138 * valid, 2 = temporarily forced */
139 SubTransactionId rd_createSubid; /* rel was created in current xact */
142 * rd_createSubid is the ID of the highest subtransaction the rel has
143 * survived into; or zero if the rel was not created in the current top
144 * transaction. This should be relied on only for optimization purposes;
145 * it is possible for new-ness to be "forgotten" (eg, after CLUSTER).
147 Form_pg_class rd_rel; /* RELATION tuple */
148 TupleDesc rd_att; /* tuple descriptor */
149 Oid rd_id; /* relation's object id */
150 List *rd_indexlist; /* list of OIDs of indexes on relation */
151 Oid rd_oidindex; /* OID of unique index on OID, if any */
152 LockInfoData rd_lockInfo; /* lock mgr's info for locking relation */
153 RuleLock *rd_rules; /* rewrite rules */
154 MemoryContext rd_rulescxt; /* private memory cxt for rd_rules, if any */
155 TriggerDesc *trigdesc; /* Trigger info, or NULL if rel has none */
158 * rd_options is set whenever rd_rel is loaded into the relcache entry.
159 * Note that you can NOT look into rd_rel for this data. NULL means "use
162 bytea *rd_options; /* parsed pg_class.reloptions */
164 /* These are non-NULL only for an index relation: */
165 Form_pg_index rd_index; /* pg_index tuple describing this index */
166 struct HeapTupleData *rd_indextuple; /* all of pg_index tuple */
167 /* "struct HeapTupleData *" avoids need to include htup.h here */
168 oidvector *rd_indclass; /* extracted pointer to rd_index field */
169 Form_pg_am rd_am; /* pg_am tuple for index's AM */
172 * index access support info (used only for an index relation)
174 * Note: only default operators and support procs for each opclass are
175 * cached, namely those with subtype zero. The arrays are indexed by
176 * strategy or support number, which is a sufficient identifier given that
179 * Note: rd_amcache is available for index AMs to cache private data about
180 * an index. This must be just a cache since it may get reset at any time
181 * (in particular, it will get reset by a relcache inval message for the
182 * index). If used, it must point to a single memory chunk palloc'd in
183 * rd_indexcxt. A relcache reset will include freeing that chunk and
184 * setting rd_amcache = NULL.
186 MemoryContext rd_indexcxt; /* private memory cxt for this stuff */
187 RelationAmInfo *rd_aminfo; /* lookup info for funcs found in pg_am */
188 Oid *rd_operator; /* OIDs of index operators */
189 RegProcedure *rd_support; /* OIDs of support procedures */
190 FmgrInfo *rd_supportinfo; /* lookup info for support procedures */
191 List *rd_indexprs; /* index expression trees, if any */
192 List *rd_indpred; /* index predicate tree, if any */
193 void *rd_amcache; /* available for use by index AM */
195 /* statistics collection area */
196 PgStat_Info pgstat_info;
199 typedef RelationData *Relation;
203 * RelationPtr is used in the executor to support index scans
204 * where we have to keep track of several index relations in an
205 * array. -cim 9/10/89
208 typedef Relation *RelationPtr;
213 * Standard contents of rd_options for heaps and generic indexes.
215 * RelationGetFillFactor() and RelationGetTargetPageFreeSpace() can only
216 * be applied to relations that use this format or a superset for
217 * private options data.
219 typedef struct StdRdOptions
221 int32 vl_len; /* required to be a bytea */
222 int fillfactor; /* page fill factor in percent (0..100) */
225 #define HEAP_MIN_FILLFACTOR 10
226 #define HEAP_DEFAULT_FILLFACTOR 100
229 * RelationGetFillFactor
230 * Returns the relation's fillfactor. Note multiple eval of argument!
232 #define RelationGetFillFactor(relation, defaultff) \
233 ((relation)->rd_options ? \
234 ((StdRdOptions *) (relation)->rd_options)->fillfactor : (defaultff))
237 * RelationGetTargetPageUsage
238 * Returns the relation's desired space usage per page in bytes.
240 #define RelationGetTargetPageUsage(relation, defaultff) \
241 (BLCKSZ * RelationGetFillFactor(relation, defaultff) / 100)
244 * RelationGetTargetPageFreeSpace
245 * Returns the relation's desired freespace per page in bytes.
247 #define RelationGetTargetPageFreeSpace(relation, defaultff) \
248 (BLCKSZ * (100 - RelationGetFillFactor(relation, defaultff)) / 100)
252 * True iff relation descriptor is valid.
254 #define RelationIsValid(relation) PointerIsValid(relation)
256 #define InvalidRelation ((Relation) NULL)
259 * RelationHasReferenceCountZero
260 * True iff relation reference count is zero.
263 * Assumes relation descriptor is valid.
265 #define RelationHasReferenceCountZero(relation) \
266 ((bool)((relation)->rd_refcnt == 0))
270 * Returns pg_class tuple for a relation.
273 * Assumes relation descriptor is valid.
275 #define RelationGetForm(relation) ((relation)->rd_rel)
279 * Returns the OID of the relation
281 #define RelationGetRelid(relation) ((relation)->rd_id)
284 * RelationGetNumberOfAttributes
285 * Returns the number of attributes in a relation.
287 #define RelationGetNumberOfAttributes(relation) ((relation)->rd_rel->relnatts)
291 * Returns tuple descriptor for a relation.
293 #define RelationGetDescr(relation) ((relation)->rd_att)
296 * RelationGetRelationName
297 * Returns the rel's name.
299 * Note that the name is only unique within the containing namespace.
301 #define RelationGetRelationName(relation) \
302 (NameStr((relation)->rd_rel->relname))
305 * RelationGetNamespace
306 * Returns the rel's namespace OID.
308 #define RelationGetNamespace(relation) \
309 ((relation)->rd_rel->relnamespace)
313 * Open the relation at the smgr level, if not already done.
315 #define RelationOpenSmgr(relation) \
317 if ((relation)->rd_smgr == NULL) \
318 smgrsetowner(&((relation)->rd_smgr), smgropen((relation)->rd_node)); \
323 * Close the relation at the smgr level, if not already done.
325 * Note: smgrclose should unhook from owner pointer, hence the Assert.
327 #define RelationCloseSmgr(relation) \
329 if ((relation)->rd_smgr != NULL) \
331 smgrclose((relation)->rd_smgr); \
332 Assert((relation)->rd_smgr == NULL); \
338 * If a rel is either temp or newly created in the current transaction,
339 * it can be assumed to be visible only to the current backend.
341 * Beware of multiple eval of argument
343 #define RELATION_IS_LOCAL(relation) \
344 ((relation)->rd_istemp || \
345 (relation)->rd_createSubid != InvalidSubTransactionId)
347 /* routines in utils/cache/relcache.c */
348 extern void RelationIncrementReferenceCount(Relation rel);
349 extern void RelationDecrementReferenceCount(Relation rel);