src/include/utils/rel.h

   1 /*-------------------------------------------------------------------------
   2  *
   3  * rel.h
   4  *        POSTGRES relation descriptor (a/k/a relcache entry) definitions.
   5  *
   6  *
   7  * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
   8  * Portions Copyright (c) 1994, Regents of the University of California
   9  *
  10  * $PostgreSQL: pgsql/src/include/utils/rel.h,v 1.83 2005/03/29 00:17:18 tgl Exp $
  11  *
  12  *-------------------------------------------------------------------------
  13  */
  14 #ifndef REL_H
  15 #define REL_H
  16
  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/relfilenode.h"
  24
  25
  26 /*
  27  * LockRelId and LockInfo really belong to lmgr.h, but it's more convenient
  28  * to declare them here so we can have a LockInfoData field in a Relation.
  29  */
  30
  31 typedef struct LockRelId
  32 {
  33         Oid                     relId;                  /* a relation identifier */
  34         Oid                     dbId;                   /* a database identifier */
  35 } LockRelId;
  36
  37 typedef struct LockInfoData
  38 {
  39         LockRelId       lockRelId;
  40 } LockInfoData;
  41
  42 typedef LockInfoData *LockInfo;
  43
  44 /*
  45  * Likewise, this struct really belongs to trigger.h, but for convenience
  46  * we put it here.
  47  */
  48 typedef struct Trigger
  49 {
  50         Oid                     tgoid;                  /* OID of trigger (pg_trigger row) */
  51         /* Remaining fields are copied from pg_trigger, see pg_trigger.h */
  52         char       *tgname;
  53         Oid                     tgfoid;
  54         int16           tgtype;
  55         bool            tgenabled;
  56         bool            tgisconstraint;
  57         Oid                     tgconstrrelid;
  58         bool            tgdeferrable;
  59         bool            tginitdeferred;
  60         int16           tgnargs;
  61         int16           tgnattr;
  62         int16      *tgattr;
  63         char      **tgargs;
  64 } Trigger;
  65
  66 typedef struct TriggerDesc
  67 {
  68         /*
  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.
  72          */
  73 #define TRIGGER_NUM_EVENT_CLASSES  3
  74
  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];
  83
  84         /* The actual array of triggers is here */
  85         Trigger    *triggers;
  86         int                     numtriggers;
  87 } TriggerDesc;
  88
  89
  90 /*
  91  * Same for the statistics collector data in Relation and scan data.
  92  */
  93 typedef struct PgStat_Info
  94 {
  95         void       *tabentry;
  96         bool            no_stats;
  97         bool            heap_scan_counted;
  98         bool            index_scan_counted;
  99 } PgStat_Info;
 100
 101
 102 /*
 103  * Here are the contents of a relation cache entry.
 104  */
 105
 106 typedef struct RelationData
 107 {
 108         RelFileNode rd_node;            /* relation physical identifier */
 109         /* use "struct" here to avoid needing to include smgr.h: */
 110         struct SMgrRelationData *rd_smgr;       /* cached file handle, or NULL */
 111         BlockNumber rd_targblock;       /* current insertion target block, or
 112                                                                  * InvalidBlockNumber */
 113         int                     rd_refcnt;              /* reference count */
 114         bool            rd_istemp;              /* rel uses the local buffer mgr */
 115         bool            rd_isnailed;    /* rel is nailed in cache */
 116         bool            rd_isvalid;             /* relcache entry is valid */
 117         char            rd_indexvalid;  /* state of rd_indexlist: 0 = not valid, 1
 118                                                                  * = valid, 2 = temporarily forced */
 119         SubTransactionId rd_createSubid;        /* rel was created in current xact */
 120
 121         /*
 122          * rd_createSubid is the ID of the highest subtransaction the rel has
 123          * survived into; or zero if the rel was not created in the current
 124          * top transaction.  This should be relied on only for optimization
 125          * purposes; it is possible for new-ness to be "forgotten" (eg, after
 126          * CLUSTER).
 127          */
 128         Form_pg_class rd_rel;           /* RELATION tuple */
 129         TupleDesc       rd_att;                 /* tuple descriptor */
 130         Oid                     rd_id;                  /* relation's object id */
 131         List       *rd_indexlist;       /* list of OIDs of indexes on relation */
 132         LockInfoData rd_lockInfo;       /* lock mgr's info for locking relation */
 133         RuleLock   *rd_rules;           /* rewrite rules */
 134         MemoryContext rd_rulescxt;      /* private memory cxt for rd_rules, if any */
 135         TriggerDesc *trigdesc;          /* Trigger info, or NULL if rel has none */
 136
 137         /* These are non-NULL only for an index relation: */
 138         Form_pg_index rd_index;         /* pg_index tuple describing this index */
 139         struct HeapTupleData *rd_indextuple;            /* all of pg_index tuple */
 140         /* "struct HeapTupleData *" avoids need to include htup.h here  */
 141         oidvector  *rd_indclass;        /* extracted pointer to rd_index field */
 142         Form_pg_am      rd_am;                  /* pg_am tuple for index's AM */
 143
 144         /*
 145          * index access support info (used only for an index relation)
 146          *
 147          * Note: only default operators and support procs for each opclass are
 148          * cached, namely those with subtype zero.      The arrays are indexed by
 149          * strategy or support number, which is a sufficient identifier given
 150          * that restriction.
 151          */
 152         MemoryContext rd_indexcxt;      /* private memory cxt for this stuff */
 153         Oid                *rd_operator;        /* OIDs of index operators */
 154         RegProcedure *rd_support;       /* OIDs of support procedures */
 155         struct FmgrInfo *rd_supportinfo;        /* lookup info for support
 156                                                                                  * procedures */
 157         /* "struct FmgrInfo" avoids need to include fmgr.h here */
 158         List       *rd_indexprs;        /* index expression trees, if any */
 159         List       *rd_indpred;         /* index predicate tree, if any */
 160
 161         /* statistics collection area */
 162         PgStat_Info pgstat_info;
 163 } RelationData;
 164
 165 typedef RelationData *Relation;
 166
 167
 168 /* ----------------
 169  *              RelationPtr is used in the executor to support index scans
 170  *              where we have to keep track of several index relations in an
 171  *              array.  -cim 9/10/89
 172  * ----------------
 173  */
 174 typedef Relation *RelationPtr;
 175
 176
 177 /*
 178  * RelationIsValid
 179  *              True iff relation descriptor is valid.
 180  */
 181 #define RelationIsValid(relation) PointerIsValid(relation)
 182
 183 #define InvalidRelation ((Relation) NULL)
 184
 185 /*
 186  * RelationHasReferenceCountZero
 187  *              True iff relation reference count is zero.
 188  *
 189  * Note:
 190  *              Assumes relation descriptor is valid.
 191  */
 192 #define RelationHasReferenceCountZero(relation) \
 193                 ((bool)((relation)->rd_refcnt == 0))
 194
 195 /*
 196  * RelationGetForm
 197  *              Returns pg_class tuple for a relation.
 198  *
 199  * Note:
 200  *              Assumes relation descriptor is valid.
 201  */
 202 #define RelationGetForm(relation) ((relation)->rd_rel)
 203
 204 /*
 205  * RelationGetRelid
 206  *              Returns the OID of the relation
 207  */
 208 #define RelationGetRelid(relation) ((relation)->rd_id)
 209
 210 /*
 211  * RelationGetNumberOfAttributes
 212  *              Returns the number of attributes in a relation.
 213  */
 214 #define RelationGetNumberOfAttributes(relation) ((relation)->rd_rel->relnatts)
 215
 216 /*
 217  * RelationGetDescr
 218  *              Returns tuple descriptor for a relation.
 219  */
 220 #define RelationGetDescr(relation) ((relation)->rd_att)
 221
 222 /*
 223  * RelationGetRelationName
 224  *              Returns the rel's name.
 225  *
 226  * Note that the name is only unique within the containing namespace.
 227  */
 228 #define RelationGetRelationName(relation) \
 229         (NameStr((relation)->rd_rel->relname))
 230
 231 /*
 232  * RelationGetNamespace
 233  *              Returns the rel's namespace OID.
 234  */
 235 #define RelationGetNamespace(relation) \
 236         ((relation)->rd_rel->relnamespace)
 237
 238 /*
 239  * RelationOpenSmgr
 240  *              Open the relation at the smgr level, if not already done.
 241  */
 242 #define RelationOpenSmgr(relation) \
 243         do { \
 244                 if ((relation)->rd_smgr == NULL) \
 245                         smgrsetowner(&((relation)->rd_smgr), smgropen((relation)->rd_node)); \
 246         } while (0)
 247
 248 /*
 249  * RelationCloseSmgr
 250  *              Close the relation at the smgr level, if not already done.
 251  *
 252  * Note: smgrclose should unhook from owner pointer, hence the Assert.
 253  */
 254 #define RelationCloseSmgr(relation) \
 255         do { \
 256                 if ((relation)->rd_smgr != NULL) \
 257                 { \
 258                         smgrclose((relation)->rd_smgr); \
 259                         Assert((relation)->rd_smgr == NULL); \
 260                 } \
 261         } while (0)
 262
 263 /*
 264  * RELATION_IS_LOCAL
 265  *              If a rel is either temp or newly created in the current transaction,
 266  *              it can be assumed to be visible only to the current backend.
 267  *
 268  * Beware of multiple eval of argument
 269  */
 270 #define RELATION_IS_LOCAL(relation) \
 271         ((relation)->rd_istemp || \
 272          (relation)->rd_createSubid != InvalidSubTransactionId)
 273
 274 /* routines in utils/cache/relcache.c */
 275 extern void RelationIncrementReferenceCount(Relation rel);
 276 extern void RelationDecrementReferenceCount(Relation rel);
 277
 278 #endif   /* REL_H */