src/include/access/genam.h

   1 /*-------------------------------------------------------------------------
   2  *
   3  * genam.h
   4  *        POSTGRES generalized index access method 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 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  * num_heap_tuples is accurate only when estimated_count is false;
  38  * otherwise it's just an estimate (currently, the estimate is the
  39  * prior value of the relation's pg_class.reltuples field).  It will
  40  * always just be an estimate during ambulkdelete.
  41  */
  42 typedef struct IndexVacuumInfo
  43 {
  44         Relation        index;                  /* the index being vacuumed */
  45         bool            vacuum_full;    /* VACUUM FULL (we have exclusive lock) */
  46         bool            analyze_only;   /* ANALYZE (without any actual vacuum) */
  47         bool            estimated_count;        /* num_heap_tuples is an estimate */
  48         int                     message_level;  /* ereport level for progress messages */
  49         double          num_heap_tuples;        /* tuples remaining in heap */
  50         BufferAccessStrategy strategy;          /* access strategy for reads */
  51 } IndexVacuumInfo;
  52
  53 /*
  54  * Struct for statistics returned by ambulkdelete and amvacuumcleanup
  55  *
  56  * This struct is normally allocated by the first ambulkdelete call and then
  57  * passed along through subsequent ones until amvacuumcleanup; however,
  58  * amvacuumcleanup must be prepared to allocate it in the case where no
  59  * ambulkdelete calls were made (because no tuples needed deletion).
  60  * Note that an index AM could choose to return a larger struct
  61  * of which this is just the first field; this provides a way for ambulkdelete
  62  * to communicate additional private data to amvacuumcleanup.
  63  *
  64  * Note: pages_removed is the amount by which the index physically shrank,
  65  * if any (ie the change in its total size on disk).  pages_deleted and
  66  * pages_free refer to free space within the index file.  Some index AMs
  67  * may compute num_index_tuples by reference to num_heap_tuples, in which
  68  * case they should copy the estimated_count field from IndexVacuumInfo.
  69  */
  70 typedef struct IndexBulkDeleteResult
  71 {
  72         BlockNumber num_pages;          /* pages remaining in index */
  73         BlockNumber pages_removed;      /* # removed during vacuum operation */
  74         bool            estimated_count;        /* num_index_tuples is an estimate */
  75         double          num_index_tuples;               /* tuples remaining */
  76         double          tuples_removed; /* # removed during vacuum operation */
  77         BlockNumber pages_deleted;      /* # unused pages in index */
  78         BlockNumber pages_free;         /* # pages available for reuse */
  79 } IndexBulkDeleteResult;
  80
  81 /* Typedef for callback function to determine if a tuple is bulk-deletable */
  82 typedef bool (*IndexBulkDeleteCallback) (ItemPointer itemptr, void *state);
  83
  84 /* struct definitions appear in relscan.h */
  85 typedef struct IndexScanDescData *IndexScanDesc;
  86 typedef struct SysScanDescData *SysScanDesc;
  87
  88
  89 /*
  90  * generalized index_ interface routines (in indexam.c)
  91  */
  92
  93 /*
  94  * IndexScanIsValid
  95  *              True iff the index scan is valid.
  96  */
  97 #define IndexScanIsValid(scan) PointerIsValid(scan)
  98
  99 extern Relation index_open(Oid relationId, LOCKMODE lockmode);
 100 extern void index_close(Relation relation, LOCKMODE lockmode);
 101
 102 extern bool index_insert(Relation indexRelation,
 103                          Datum *values, bool *isnull,
 104                          ItemPointer heap_t_ctid,
 105                          Relation heapRelation,
 106                          bool check_uniqueness);
 107
 108 extern IndexScanDesc index_beginscan(Relation heapRelation,
 109                                 Relation indexRelation,
 110                                 Snapshot snapshot,
 111                                 int nkeys, ScanKey key);
 112 extern IndexScanDesc index_beginscan_bitmap(Relation indexRelation,
 113                                           Snapshot snapshot,
 114                                           int nkeys, ScanKey key);
 115 extern void index_rescan(IndexScanDesc scan, ScanKey key);
 116 extern void index_endscan(IndexScanDesc scan);
 117 extern void index_markpos(IndexScanDesc scan);
 118 extern void index_restrpos(IndexScanDesc scan);
 119 extern HeapTuple index_getnext(IndexScanDesc scan, ScanDirection direction);
 120 extern int64 index_getbitmap(IndexScanDesc scan, TIDBitmap *bitmap);
 121
 122 extern IndexBulkDeleteResult *index_bulk_delete(IndexVacuumInfo *info,
 123                                   IndexBulkDeleteResult *stats,
 124                                   IndexBulkDeleteCallback callback,
 125                                   void *callback_state);
 126 extern IndexBulkDeleteResult *index_vacuum_cleanup(IndexVacuumInfo *info,
 127                                          IndexBulkDeleteResult *stats);
 128 extern RegProcedure index_getprocid(Relation irel, AttrNumber attnum,
 129                                 uint16 procnum);
 130 extern FmgrInfo *index_getprocinfo(Relation irel, AttrNumber attnum,
 131                                   uint16 procnum);
 132
 133 /*
 134  * index access method support routines (in genam.c)
 135  */
 136 extern IndexScanDesc RelationGetIndexScan(Relation indexRelation,
 137                                          int nkeys, ScanKey key);
 138 extern void IndexScanEnd(IndexScanDesc scan);
 139
 140 /*
 141  * heap-or-index access to system catalogs (in genam.c)
 142  */
 143 extern SysScanDesc systable_beginscan(Relation heapRelation,
 144                                    Oid indexId,
 145                                    bool indexOK,
 146                                    Snapshot snapshot,
 147                                    int nkeys, ScanKey key);
 148 extern HeapTuple systable_getnext(SysScanDesc sysscan);
 149 extern bool systable_recheck_tuple(SysScanDesc sysscan, HeapTuple tup);
 150 extern void systable_endscan(SysScanDesc sysscan);
 151 extern SysScanDesc systable_beginscan_ordered(Relation heapRelation,
 152                                                                                           Relation indexRelation,
 153                                                                                           Snapshot snapshot,
 154                                                                                           int nkeys, ScanKey key);
 155 extern HeapTuple systable_getnext_ordered(SysScanDesc sysscan,
 156                                                                                   ScanDirection direction);
 157 extern void systable_endscan_ordered(SysScanDesc sysscan);
 158
 159 #endif   /* GENAM_H */