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) 1996-2009, PostgreSQL Global Development Group
   8  * Portions Copyright (c) 1994, Regents of the University of California
   9  *
  10  * $PostgreSQL$
  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 "fmgr.h"
  22 #include "nodes/bitmapset.h"
  23 #include "rewrite/prs2lock.h"
  24 #include "storage/block.h"
  25 #include "storage/relfilenode.h"
  26 #include "utils/relcache.h"
  27
  28
  29 /*
  30  * LockRelId and LockInfo really belong to lmgr.h, but it's more convenient
  31  * to declare them here so we can have a LockInfoData field in a Relation.
  32  */
  33
  34 typedef struct LockRelId
  35 {
  36         Oid                     relId;                  /* a relation identifier */
  37         Oid                     dbId;                   /* a database identifier */
  38 } LockRelId;
  39
  40 typedef struct LockInfoData
  41 {
  42         LockRelId       lockRelId;
  43 } LockInfoData;
  44
  45 typedef LockInfoData *LockInfo;
  46
  47 /*
  48  * Likewise, this struct really belongs to trigger.h, but for convenience
  49  * we put it here.
  50  */
  51 typedef struct Trigger
  52 {
  53         Oid                     tgoid;                  /* OID of trigger (pg_trigger row) */
  54         /* Remaining fields are copied from pg_trigger, see pg_trigger.h */
  55         char       *tgname;
  56         Oid                     tgfoid;
  57         int16           tgtype;
  58         char            tgenabled;
  59         bool            tgisconstraint;
  60         Oid                     tgconstrrelid;
  61         Oid                     tgconstraint;
  62         bool            tgdeferrable;
  63         bool            tginitdeferred;
  64         int16           tgnargs;
  65         int16           tgnattr;
  66         int16      *tgattr;
  67         char      **tgargs;
  68 } Trigger;
  69
  70 typedef struct TriggerDesc
  71 {
  72         /*
  73          * Index data to identify which triggers are which.  Since each trigger
  74          * can appear in more than one class, for each class we provide a list of
  75          * integer indexes into the triggers array.  The class codes are defined
  76          * by TRIGGER_EVENT_xxx macros in commands/trigger.h.
  77          */
  78 #define TRIGGER_NUM_EVENT_CLASSES  4
  79
  80         uint16          n_before_statement[TRIGGER_NUM_EVENT_CLASSES];
  81         uint16          n_before_row[TRIGGER_NUM_EVENT_CLASSES];
  82         uint16          n_after_row[TRIGGER_NUM_EVENT_CLASSES];
  83         uint16          n_after_statement[TRIGGER_NUM_EVENT_CLASSES];
  84         int                *tg_before_statement[TRIGGER_NUM_EVENT_CLASSES];
  85         int                *tg_before_row[TRIGGER_NUM_EVENT_CLASSES];
  86         int                *tg_after_row[TRIGGER_NUM_EVENT_CLASSES];
  87         int                *tg_after_statement[TRIGGER_NUM_EVENT_CLASSES];
  88
  89         /* The actual array of triggers is here */
  90         Trigger    *triggers;
  91         int                     numtriggers;
  92 } TriggerDesc;
  93
  94
  95 /*
  96  * Cached lookup information for the index access method functions defined
  97  * by the pg_am row associated with an index relation.
  98  */
  99 typedef struct RelationAmInfo
 100 {
 101         FmgrInfo        aminsert;
 102         FmgrInfo        ambeginscan;
 103         FmgrInfo        amgettuple;
 104         FmgrInfo        amgetbitmap;
 105         FmgrInfo        amrescan;
 106         FmgrInfo        amendscan;
 107         FmgrInfo        ammarkpos;
 108         FmgrInfo        amrestrpos;
 109         FmgrInfo        ambuild;
 110         FmgrInfo        ambulkdelete;
 111         FmgrInfo        amvacuumcleanup;
 112         FmgrInfo        amcostestimate;
 113         FmgrInfo        amoptions;
 114 } RelationAmInfo;
 115
 116
 117 /*
 118  * Here are the contents of a relation cache entry.
 119  */
 120
 121 typedef struct RelationData
 122 {
 123         RelFileNode rd_node;            /* relation physical identifier */
 124         /* use "struct" here to avoid needing to include smgr.h: */
 125         struct SMgrRelationData *rd_smgr;       /* cached file handle, or NULL */
 126         BlockNumber rd_targblock;       /* current insertion target block, or
 127                                                                  * InvalidBlockNumber */
 128         int                     rd_refcnt;              /* reference count */
 129         bool            rd_istemp;              /* rel uses the local buffer mgr */
 130         bool            rd_isnailed;    /* rel is nailed in cache */
 131         bool            rd_isvalid;             /* relcache entry is valid */
 132         char            rd_indexvalid;  /* state of rd_indexlist: 0 = not valid, 1 =
 133                                                                  * valid, 2 = temporarily forced */
 134         SubTransactionId rd_createSubid;        /* rel was created in current xact */
 135         SubTransactionId rd_newRelfilenodeSubid;        /* new relfilenode assigned in
 136                                                                                                  * current xact */
 137
 138         /*
 139          * rd_createSubid is the ID of the highest subtransaction the rel has
 140          * survived into; or zero if the rel was not created in the current top
 141          * transaction.  This should be relied on only for optimization purposes;
 142          * it is possible for new-ness to be "forgotten" (eg, after CLUSTER).
 143          * Likewise, rd_newRelfilenodeSubid is the ID of the highest
 144          * subtransaction the relfilenode change has survived into, or zero if not
 145          * changed in the current transaction (or we have forgotten changing it).
 146          */
 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         Bitmapset  *rd_indexattr;       /* identifies columns used in indexes */
 152         Oid                     rd_oidindex;    /* OID of unique index on OID, if any */
 153         LockInfoData rd_lockInfo;       /* lock mgr's info for locking relation */
 154         RuleLock   *rd_rules;           /* rewrite rules */
 155         MemoryContext rd_rulescxt;      /* private memory cxt for rd_rules, if any */
 156         TriggerDesc *trigdesc;          /* Trigger info, or NULL if rel has none */
 157
 158         /*
 159          * rd_options is set whenever rd_rel is loaded into the relcache entry.
 160          * Note that you can NOT look into rd_rel for this data.  NULL means "use
 161          * defaults".
 162          */
 163         bytea      *rd_options;         /* parsed pg_class.reloptions */
 164
 165         /* These are non-NULL only for an index relation: */
 166         Form_pg_index rd_index;         /* pg_index tuple describing this index */
 167         struct HeapTupleData *rd_indextuple;            /* all of pg_index tuple */
 168         /* "struct HeapTupleData *" avoids need to include htup.h here  */
 169         Form_pg_am      rd_am;                  /* pg_am tuple for index's AM */
 170
 171         /*
 172          * index access support info (used only for an index relation)
 173          *
 174          * Note: only default operators and support procs for each opclass are
 175          * cached, namely those with lefttype and righttype equal to the opclass's
 176          * opcintype.  The arrays are indexed by strategy or support number, which
 177          * is a sufficient identifier given that restriction.
 178          *
 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.
 185          */
 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_opfamily;        /* OIDs of op families for each index col */
 189         Oid                *rd_opcintype;       /* OIDs of opclass declared input data types */
 190         Oid                *rd_operator;        /* OIDs of index operators */
 191         RegProcedure *rd_support;       /* OIDs of support procedures */
 192         FmgrInfo   *rd_supportinfo; /* lookup info for support procedures */
 193         int16      *rd_indoption;       /* per-column AM-specific flags */
 194         List       *rd_indexprs;        /* index expression trees, if any */
 195         List       *rd_indpred;         /* index predicate tree, if any */
 196         void       *rd_amcache;         /* available for use by index AM */
 197
 198         /*
 199          * sizes of the free space and visibility map forks, or InvalidBlockNumber
 200          * if not known yet
 201          */
 202         BlockNumber     rd_fsm_nblocks;
 203         BlockNumber     rd_vm_nblocks;
 204
 205         /* use "struct" here to avoid needing to include pgstat.h: */
 206         struct PgStat_TableStatus *pgstat_info;         /* statistics collection area */
 207 } RelationData;
 208
 209 /*
 210  * StdRdOptions
 211  *              Standard contents of rd_options for heaps and generic indexes.
 212  *
 213  * RelationGetFillFactor() and RelationGetTargetPageFreeSpace() can only
 214  * be applied to relations that use this format or a superset for
 215  * private options data.
 216  */
 217  /* autovacuum-related reloptions. */
 218 typedef struct AutoVacOpts
 219 {
 220         bool    enabled;
 221         int     vacuum_threshold;
 222         int     analyze_threshold;
 223         int     vacuum_cost_delay;
 224         int     vacuum_cost_limit;
 225         int     freeze_min_age;
 226         int     freeze_max_age;
 227         int             freeze_table_age;
 228         float8  vacuum_scale_factor;
 229         float8  analyze_scale_factor;
 230 } AutoVacOpts;
 231
 232 typedef struct StdRdOptions
 233 {
 234         int32           vl_len_;                /* varlena header (do not touch directly!) */
 235         int                     fillfactor;             /* page fill factor in percent (0..100) */
 236         AutoVacOpts autovacuum;     /* autovacuum-related options */
 237 } StdRdOptions;
 238
 239 #define HEAP_MIN_FILLFACTOR                     10
 240 #define HEAP_DEFAULT_FILLFACTOR         100
 241
 242 /*
 243  * RelationGetFillFactor
 244  *              Returns the relation's fillfactor.  Note multiple eval of argument!
 245  */
 246 #define RelationGetFillFactor(relation, defaultff) \
 247         ((relation)->rd_options ? \
 248          ((StdRdOptions *) (relation)->rd_options)->fillfactor : (defaultff))
 249
 250 /*
 251  * RelationGetTargetPageUsage
 252  *              Returns the relation's desired space usage per page in bytes.
 253  */
 254 #define RelationGetTargetPageUsage(relation, defaultff) \
 255         (BLCKSZ * RelationGetFillFactor(relation, defaultff) / 100)
 256
 257 /*
 258  * RelationGetTargetPageFreeSpace
 259  *              Returns the relation's desired freespace per page in bytes.
 260  */
 261 #define RelationGetTargetPageFreeSpace(relation, defaultff) \
 262         (BLCKSZ * (100 - RelationGetFillFactor(relation, defaultff)) / 100)
 263
 264 /*
 265  * RelationIsValid
 266  *              True iff relation descriptor is valid.
 267  */
 268 #define RelationIsValid(relation) PointerIsValid(relation)
 269
 270 #define InvalidRelation ((Relation) NULL)
 271
 272 /*
 273  * RelationHasReferenceCountZero
 274  *              True iff relation reference count is zero.
 275  *
 276  * Note:
 277  *              Assumes relation descriptor is valid.
 278  */
 279 #define RelationHasReferenceCountZero(relation) \
 280                 ((bool)((relation)->rd_refcnt == 0))
 281
 282 /*
 283  * RelationGetForm
 284  *              Returns pg_class tuple for a relation.
 285  *
 286  * Note:
 287  *              Assumes relation descriptor is valid.
 288  */
 289 #define RelationGetForm(relation) ((relation)->rd_rel)
 290
 291 /*
 292  * RelationGetRelid
 293  *              Returns the OID of the relation
 294  */
 295 #define RelationGetRelid(relation) ((relation)->rd_id)
 296
 297 /*
 298  * RelationGetNumberOfAttributes
 299  *              Returns the number of attributes in a relation.
 300  */
 301 #define RelationGetNumberOfAttributes(relation) ((relation)->rd_rel->relnatts)
 302
 303 /*
 304  * RelationGetDescr
 305  *              Returns tuple descriptor for a relation.
 306  */
 307 #define RelationGetDescr(relation) ((relation)->rd_att)
 308
 309 /*
 310  * RelationGetRelationName
 311  *              Returns the rel's name.
 312  *
 313  * Note that the name is only unique within the containing namespace.
 314  */
 315 #define RelationGetRelationName(relation) \
 316         (NameStr((relation)->rd_rel->relname))
 317
 318 /*
 319  * RelationGetNamespace
 320  *              Returns the rel's namespace OID.
 321  */
 322 #define RelationGetNamespace(relation) \
 323         ((relation)->rd_rel->relnamespace)
 324
 325 /*
 326  * RelationOpenSmgr
 327  *              Open the relation at the smgr level, if not already done.
 328  */
 329 #define RelationOpenSmgr(relation) \
 330         do { \
 331                 if ((relation)->rd_smgr == NULL) \
 332                         smgrsetowner(&((relation)->rd_smgr), smgropen((relation)->rd_node)); \
 333         } while (0)
 334
 335 /*
 336  * RelationCloseSmgr
 337  *              Close the relation at the smgr level, if not already done.
 338  *
 339  * Note: smgrclose should unhook from owner pointer, hence the Assert.
 340  */
 341 #define RelationCloseSmgr(relation) \
 342         do { \
 343                 if ((relation)->rd_smgr != NULL) \
 344                 { \
 345                         smgrclose((relation)->rd_smgr); \
 346                         Assert((relation)->rd_smgr == NULL); \
 347                 } \
 348         } while (0)
 349
 350 /*
 351  * RELATION_IS_LOCAL
 352  *              If a rel is either temp or newly created in the current transaction,
 353  *              it can be assumed to be visible only to the current backend.
 354  *
 355  * Beware of multiple eval of argument
 356  */
 357 #define RELATION_IS_LOCAL(relation) \
 358         ((relation)->rd_istemp || \
 359          (relation)->rd_createSubid != InvalidSubTransactionId)
 360
 361 /* routines in utils/cache/relcache.c */
 362 extern void RelationIncrementReferenceCount(Relation rel);
 363 extern void RelationDecrementReferenceCount(Relation rel);
 364
 365 #endif   /* REL_H */