/*------------------------------------------------------------------------- * * amapi.h * API for Postgres index access methods. * * Copyright (c) 2015-2021, PostgreSQL Global Development Group * * src/include/access/amapi.h * *------------------------------------------------------------------------- */ #ifndef AMAPI_H #define AMAPI_H #include "access/genam.h" /* * We don't wish to include planner header files here, since most of an index * AM's implementation isn't concerned with those data structures. To allow * declaring amcostestimate_function here, use forward struct references. */ struct PlannerInfo; struct IndexPath; /* Likewise, this file shouldn't depend on execnodes.h. */ struct IndexInfo; /* * Properties for amproperty API. This list covers properties known to the * core code, but an index AM can define its own properties, by matching the * string property name. */ typedef enum IndexAMProperty { AMPROP_UNKNOWN = 0, /* anything not known to core code */ AMPROP_ASC, /* column properties */ AMPROP_DESC, AMPROP_NULLS_FIRST, AMPROP_NULLS_LAST, AMPROP_ORDERABLE, AMPROP_DISTANCE_ORDERABLE, AMPROP_RETURNABLE, AMPROP_SEARCH_ARRAY, AMPROP_SEARCH_NULLS, AMPROP_CLUSTERABLE, /* index properties */ AMPROP_INDEX_SCAN, AMPROP_BITMAP_SCAN, AMPROP_BACKWARD_SCAN, AMPROP_CAN_ORDER, /* AM properties */ AMPROP_CAN_UNIQUE, AMPROP_CAN_MULTI_COL, AMPROP_CAN_EXCLUDE, AMPROP_CAN_INCLUDE } IndexAMProperty; /* * We use lists of this struct type to keep track of both operators and * support functions while building or adding to an opclass or opfamily. * amadjustmembers functions receive lists of these structs, and are allowed * to alter their "ref" fields. * * The "ref" fields define how the pg_amop or pg_amproc entry should depend * on the associated objects (that is, which dependency type to use, and * which opclass or opfamily it should depend on). * * If ref_is_hard is true, the entry will have a NORMAL dependency on the * operator or support func, and an INTERNAL dependency on the opclass or * opfamily. This forces the opclass or opfamily to be dropped if the * operator or support func is dropped, and requires the CASCADE option * to do so. Nor will ALTER OPERATOR FAMILY DROP be allowed. This is * the right behavior for objects that are essential to an opclass. * * If ref_is_hard is false, the entry will have an AUTO dependency on the * operator or support func, and also an AUTO dependency on the opclass or * opfamily. This allows ALTER OPERATOR FAMILY DROP, and causes that to * happen automatically if the operator or support func is dropped. This * is the right behavior for inessential ("loose") objects. */ typedef struct OpFamilyMember { bool is_func; /* is this an operator, or support func? */ Oid object; /* operator or support func's OID */ int number; /* strategy or support func number */ Oid lefttype; /* lefttype */ Oid righttype; /* righttype */ Oid sortfamily; /* ordering operator's sort opfamily, or 0 */ bool ref_is_hard; /* hard or soft dependency? */ bool ref_is_family; /* is dependency on opclass or opfamily? */ Oid refobjid; /* OID of opclass or opfamily */ } OpFamilyMember; /* * Callback function signatures --- see indexam.sgml for more info. */ /* build new index */ typedef IndexBuildResult *(*ambuild_function) (Relation heapRelation, Relation indexRelation, struct IndexInfo *indexInfo); /* build empty index */ typedef void (*ambuildempty_function) (Relation indexRelation); /* insert this tuple */ typedef bool (*aminsert_function) (Relation indexRelation, Datum *values, bool *isnull, ItemPointer heap_tid, Relation heapRelation, IndexUniqueCheck checkUnique, bool indexUnchanged, struct IndexInfo *indexInfo); /* bulk delete */ typedef IndexBulkDeleteResult *(*ambulkdelete_function) (IndexVacuumInfo *info, IndexBulkDeleteResult *stats, IndexBulkDeleteCallback callback, void *callback_state); /* post-VACUUM cleanup */ typedef IndexBulkDeleteResult *(*amvacuumcleanup_function) (IndexVacuumInfo *info, IndexBulkDeleteResult *stats); /* can indexscan return IndexTuples? */ typedef bool (*amcanreturn_function) (Relation indexRelation, int attno); /* estimate cost of an indexscan */ typedef void (*amcostestimate_function) (struct PlannerInfo *root, struct IndexPath *path, double loop_count, Cost *indexStartupCost, Cost *indexTotalCost, Selectivity *indexSelectivity, double *indexCorrelation, double *indexPages); /* parse index reloptions */ typedef bytea *(*amoptions_function) (Datum reloptions, bool validate); /* report AM, index, or index column property */ typedef bool (*amproperty_function) (Oid index_oid, int attno, IndexAMProperty prop, const char *propname, bool *res, bool *isnull); /* name of phase as used in progress reporting */ typedef char *(*ambuildphasename_function) (int64 phasenum); /* validate definition of an opclass for this AM */ typedef bool (*amvalidate_function) (Oid opclassoid); /* validate operators and support functions to be added to an opclass/family */ typedef void (*amadjustmembers_function) (Oid opfamilyoid, Oid opclassoid, List *operators, List *functions); /* prepare for index scan */ typedef IndexScanDesc (*ambeginscan_function) (Relation indexRelation, int nkeys, int norderbys); /* (re)start index scan */ typedef void (*amrescan_function) (IndexScanDesc scan, ScanKey keys, int nkeys, ScanKey orderbys, int norderbys); /* next valid tuple */ typedef bool (*amgettuple_function) (IndexScanDesc scan, ScanDirection direction); /* fetch all valid tuples */ typedef int64 (*amgetbitmap_function) (IndexScanDesc scan, TIDBitmap *tbm); /* end index scan */ typedef void (*amendscan_function) (IndexScanDesc scan); /* mark current scan position */ typedef void (*ammarkpos_function) (IndexScanDesc scan); /* restore marked scan position */ typedef void (*amrestrpos_function) (IndexScanDesc scan); /* * Callback function signatures - for parallel index scans. */ /* estimate size of parallel scan descriptor */ typedef Size (*amestimateparallelscan_function) (void); /* prepare for parallel index scan */ typedef void (*aminitparallelscan_function) (void *target); /* (re)start parallel index scan */ typedef void (*amparallelrescan_function) (IndexScanDesc scan); /* * API struct for an index AM. Note this must be stored in a single palloc'd * chunk of memory. */ typedef struct IndexAmRoutine { NodeTag type; /* * Total number of strategies (operators) by which we can traverse/search * this AM. Zero if AM does not have a fixed set of strategy assignments. */ uint16 amstrategies; /* total number of support functions that this AM uses */ uint16 amsupport; /* opclass options support function number or 0 */ uint16 amoptsprocnum; /* does AM support ORDER BY indexed column's value? */ bool amcanorder; /* does AM support ORDER BY result of an operator on indexed column? */ bool amcanorderbyop; /* does AM support backward scanning? */ bool amcanbackward; /* does AM support UNIQUE indexes? */ bool amcanunique; /* does AM support multi-column indexes? */ bool amcanmulticol; /* does AM require scans to have a constraint on the first index column? */ bool amoptionalkey; /* does AM handle ScalarArrayOpExpr quals? */ bool amsearcharray; /* does AM handle IS NULL/IS NOT NULL quals? */ bool amsearchnulls; /* can index storage data type differ from column data type? */ bool amstorage; /* can an index of this type be clustered on? */ bool amclusterable; /* does AM handle predicate locks? */ bool ampredlocks; /* does AM support parallel scan? */ bool amcanparallel; /* does AM support columns included with clause INCLUDE? */ bool amcaninclude; /* does AM use maintenance_work_mem? */ bool amusemaintenanceworkmem; /* OR of parallel vacuum flags. See vacuum.h for flags. */ uint8 amparallelvacuumoptions; /* type of data stored in index, or InvalidOid if variable */ Oid amkeytype; /* * If you add new properties to either the above or the below lists, then * they should also (usually) be exposed via the property API (see * IndexAMProperty at the top of the file, and utils/adt/amutils.c). */ /* interface functions */ ambuild_function ambuild; ambuildempty_function ambuildempty; aminsert_function aminsert; ambulkdelete_function ambulkdelete; amvacuumcleanup_function amvacuumcleanup; amcanreturn_function amcanreturn; /* can be NULL */ amcostestimate_function amcostestimate; amoptions_function amoptions; amproperty_function amproperty; /* can be NULL */ ambuildphasename_function ambuildphasename; /* can be NULL */ amvalidate_function amvalidate; amadjustmembers_function amadjustmembers; /* can be NULL */ ambeginscan_function ambeginscan; amrescan_function amrescan; amgettuple_function amgettuple; /* can be NULL */ amgetbitmap_function amgetbitmap; /* can be NULL */ amendscan_function amendscan; ammarkpos_function ammarkpos; /* can be NULL */ amrestrpos_function amrestrpos; /* can be NULL */ /* interface functions to support parallel index scans */ amestimateparallelscan_function amestimateparallelscan; /* can be NULL */ aminitparallelscan_function aminitparallelscan; /* can be NULL */ amparallelrescan_function amparallelrescan; /* can be NULL */ } IndexAmRoutine; /* Functions in access/index/amapi.c */ extern IndexAmRoutine *GetIndexAmRoutine(Oid amhandler); extern IndexAmRoutine *GetIndexAmRoutineByAmId(Oid amoid, bool noerror); #endif /* AMAPI_H */