src/include/access/genam.h

   1 /*-------------------------------------------------------------------------
   2  *
   3  * genam.h
   4  *        POSTGRES generalized index access method definitions.
   5  *
   6  *
   7  * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
   8  * Portions Copyright (c) 1994, Regents of the University of California
   9  *
  10  * $PostgreSQL$
  11  *
  12  *-------------------------------------------------------------------------
  13  */
  14 #ifndef GENAM_H
  15 #define GENAM_H
  16
  17 #include "access/sdir.h"
  18 #include "access/skey.h"
  19 #include "nodes/tidbitmap.h"
  20 #include "storage/buf.h"
  21 #include "storage/lock.h"
  22 #include "utils/relcache.h"
  23 #include "utils/snapshot.h"
  24
  25 /*
  26  * Struct for statistics returned by ambuild
  27  */
  28 typedef struct IndexBuildResult
  29 {
  30         double          heap_tuples;    /* # of tuples seen in parent table */
  31         double          index_tuples;   /* # of tuples inserted into index */
  32 } IndexBuildResult;
  33
  34 /*
  35  * Struct for input arguments passed to ambulkdelete and amvacuumcleanup
  36  *
  37  * Note that num_heap_tuples will not be valid during ambulkdelete,
  38  * only amvacuumcleanup.
  39  */
  40 typedef struct IndexVacuumInfo
  41 {
  42         Relation        index;                  /* the index being vacuumed */
  43         bool            vacuum_full;    /* VACUUM FULL (we have exclusive lock) */
  44         int                     message_level;  /* ereport level for progress messages */
  45         double          num_heap_tuples;        /* tuples remaining in heap */
  46         BufferAccessStrategy strategy;          /* access strategy for reads */
  47 } IndexVacuumInfo;
  48
  49 /*
  50  * Struct for statistics returned by ambulkdelete and amvacuumcleanup
  51  *
  52  * This struct is normally allocated by the first ambulkdelete call and then
  53  * passed along through subsequent ones until amvacuumcleanup; however,
  54  * amvacuumcleanup must be prepared to allocate it in the case where no
  55  * ambulkdelete calls were made (because no tuples needed deletion).
  56  * Note that an index AM could choose to return a larger struct
  57  * of which this is just the first field; this provides a way for ambulkdelete
  58  * to communicate additional private data to amvacuumcleanup.
  59  *
  60  * Note: pages_removed is the amount by which the index physically shrank,
  61  * if any (ie the change in its total size on disk).  pages_deleted and
  62  * pages_free refer to free space within the index file.
  63  */
  64 typedef struct IndexBulkDeleteResult
  65 {
  66         BlockNumber num_pages;          /* pages remaining in index */
  67         BlockNumber pages_removed;      /* # removed during vacuum operation */
  68         double          num_index_tuples;               /* tuples remaining */
  69         double          tuples_removed; /* # removed during vacuum operation */
  70         BlockNumber pages_deleted;      /* # unused pages in index */
  71         BlockNumber pages_free;         /* # pages available for reuse */
  72 } IndexBulkDeleteResult;
  73
  74 /* Typedef for callback function to determine if a tuple is bulk-deletable */
  75 typedef bool (*IndexBulkDeleteCallback) (ItemPointer itemptr, void *state);
  76
  77 /* struct definitions appear in relscan.h */
  78 typedef struct IndexScanDescData *IndexScanDesc;
  79 typedef struct SysScanDescData *SysScanDesc;
  80
  81
  82 /*
  83  * generalized index_ interface routines (in indexam.c)
  84  */
  85
  86 /*
  87  * IndexScanIsValid
  88  *              True iff the index scan is valid.
  89  */
  90 #define IndexScanIsValid(scan) PointerIsValid(scan)
  91
  92 extern Relation index_open(Oid relationId, LOCKMODE lockmode);
  93 extern void index_close(Relation relation, LOCKMODE lockmode);
  94
  95 extern bool index_insert(Relation indexRelation,
  96                          Datum *values, bool *isnull,
  97                          ItemPointer heap_t_ctid,
  98                          Relation heapRelation,
  99                          bool check_uniqueness);
 100
 101 extern IndexScanDesc index_beginscan(Relation heapRelation,
 102                                 Relation indexRelation,
 103                                 Snapshot snapshot,
 104                                 int nkeys, ScanKey key);
 105 extern IndexScanDesc index_beginscan_bitmap(Relation indexRelation,
 106                                           Snapshot snapshot,
 107                                           int nkeys, ScanKey key);
 108 extern void index_rescan(IndexScanDesc scan, ScanKey key);
 109 extern void index_endscan(IndexScanDesc scan);
 110 extern void index_markpos(IndexScanDesc scan);
 111 extern void index_restrpos(IndexScanDesc scan);
 112 extern HeapTuple index_getnext(IndexScanDesc scan, ScanDirection direction);
 113 extern int64 index_getbitmap(IndexScanDesc scan, TIDBitmap *bitmap);
 114
 115 extern IndexBulkDeleteResult *index_bulk_delete(IndexVacuumInfo *info,
 116                                   IndexBulkDeleteResult *stats,
 117                                   IndexBulkDeleteCallback callback,
 118                                   void *callback_state);
 119 extern IndexBulkDeleteResult *index_vacuum_cleanup(IndexVacuumInfo *info,
 120                                          IndexBulkDeleteResult *stats);
 121 extern RegProcedure index_getprocid(Relation irel, AttrNumber attnum,
 122                                 uint16 procnum);
 123 extern FmgrInfo *index_getprocinfo(Relation irel, AttrNumber attnum,
 124                                   uint16 procnum);
 125
 126 /*
 127  * index access method support routines (in genam.c)
 128  */
 129 extern IndexScanDesc RelationGetIndexScan(Relation indexRelation,
 130                                          int nkeys, ScanKey key);
 131 extern void IndexScanEnd(IndexScanDesc scan);
 132
 133 /*
 134  * heap-or-index access to system catalogs (in genam.c)
 135  */
 136 extern SysScanDesc systable_beginscan(Relation heapRelation,
 137                                    Oid indexId,
 138                                    bool indexOK,
 139                                    Snapshot snapshot,
 140                                    int nkeys, ScanKey key);
 141 extern HeapTuple systable_getnext(SysScanDesc sysscan);
 142 extern bool systable_recheck_tuple(SysScanDesc sysscan, HeapTuple tup);
 143 extern void systable_endscan(SysScanDesc sysscan);
 144 extern SysScanDesc systable_beginscan_ordered(Relation heapRelation,
 145                                                                                           Relation indexRelation,
 146                                                                                           Snapshot snapshot,
 147                                                                                           int nkeys, ScanKey key);
 148 extern HeapTuple systable_getnext_ordered(SysScanDesc sysscan,
 149                                                                                   ScanDirection direction);
 150 extern void systable_endscan_ordered(SysScanDesc sysscan);
 151
 152 #endif   /* GENAM_H */