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) 1996-2003, 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 1.74 2004/05/08 19:09:25 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           tgattr[FUNC_MAX_ARGS];
  62         char      **tgargs;
  63 } Trigger;
  64
  65 typedef struct TriggerDesc
  66 {
  67         /*
  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.
  71          */
  72 #define TRIGGER_NUM_EVENT_CLASSES  3
  73
  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];
  82
  83         /* The actual array of triggers is here */
  84         Trigger    *triggers;
  85         int                     numtriggers;
  86 } TriggerDesc;
  87
  88
  89 /*
  90  * Same for the statistics collector data in Relation and scan data.
  91  */
  92 typedef struct PgStat_Info
  93 {
  94         void       *tabentry;
  95         bool            no_stats;
  96         bool            heap_scan_counted;
  97         bool            index_scan_counted;
  98 } PgStat_Info;
  99
 100
 101 /*
 102  * Here are the contents of a relation cache entry.
 103  */
 104
 105 typedef struct RelationData
 106 {
 107         RelFileNode rd_node;            /* relation physical identifier */
 108         /* use "struct" here to avoid needing to include smgr.h: */
 109         struct SMgrRelationData *rd_smgr; /* cached file handle, or NULL */
 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 */
 114
 115         /*
 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).
 118          */
 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 */
 132
 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 */
 138
 139         /*
 140          * index access support info (used only for an index relation)
 141          *
 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
 145          * that restriction.
 146          */
 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
 151                                                                                  * procedures */
 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 */
 155
 156         /* statistics collection area */
 157         PgStat_Info pgstat_info;
 158 } RelationData;
 159
 160 typedef RelationData *Relation;
 161
 162
 163 /* ----------------
 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
 167  * ----------------
 168  */
 169 typedef Relation *RelationPtr;
 170
 171
 172 /*
 173  * RelationIsValid
 174  *              True iff relation descriptor is valid.
 175  */
 176 #define RelationIsValid(relation) PointerIsValid(relation)
 177
 178 #define InvalidRelation ((Relation) NULL)
 179
 180 /*
 181  * RelationHasReferenceCountZero
 182  *              True iff relation reference count is zero.
 183  *
 184  * Note:
 185  *              Assumes relation descriptor is valid.
 186  */
 187 #define RelationHasReferenceCountZero(relation) \
 188                 ((bool)((relation)->rd_refcnt == 0))
 189
 190 /*
 191  * RelationSetReferenceCount
 192  *              Sets relation reference count.
 193  */
 194 #define RelationSetReferenceCount(relation,count) \
 195         ((relation)->rd_refcnt = (count))
 196
 197 /*
 198  * RelationIncrementReferenceCount
 199  *              Increments relation reference count.
 200  */
 201 #define RelationIncrementReferenceCount(relation) \
 202         ((relation)->rd_refcnt += 1)
 203
 204 /*
 205  * RelationDecrementReferenceCount
 206  *              Decrements relation reference count.
 207  */
 208 #define RelationDecrementReferenceCount(relation) \
 209         (AssertMacro((relation)->rd_refcnt > 0), \
 210          (relation)->rd_refcnt -= 1)
 211
 212 /*
 213  * RelationGetForm
 214  *              Returns pg_class tuple for a relation.
 215  *
 216  * Note:
 217  *              Assumes relation descriptor is valid.
 218  */
 219 #define RelationGetForm(relation) ((relation)->rd_rel)
 220
 221 /*
 222  * RelationGetRelid
 223  *              Returns the OID of the relation
 224  */
 225 #define RelationGetRelid(relation) ((relation)->rd_id)
 226
 227 /*
 228  * RelationGetNumberOfAttributes
 229  *              Returns the number of attributes in a relation.
 230  */
 231 #define RelationGetNumberOfAttributes(relation) ((relation)->rd_rel->relnatts)
 232
 233 /*
 234  * RelationGetDescr
 235  *              Returns tuple descriptor for a relation.
 236  */
 237 #define RelationGetDescr(relation) ((relation)->rd_att)
 238
 239 /*
 240  * RelationGetRelationName
 241  *              Returns the rel's name.
 242  *
 243  * Note that the name is only unique within the containing namespace.
 244  */
 245 #define RelationGetRelationName(relation) \
 246         (NameStr((relation)->rd_rel->relname))
 247
 248 /*
 249  * RelationGetNamespace
 250  *              Returns the rel's namespace OID.
 251  */
 252 #define RelationGetNamespace(relation) \
 253         ((relation)->rd_rel->relnamespace)
 254
 255 #endif   /* REL_H */