diff options
Diffstat (limited to 'src/include/nodes/execnodes.h')
| -rw-r--r-- | src/include/nodes/execnodes.h | 25 |
1 files changed, 20 insertions, 5 deletions
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h index da1ae708722..35a0ab3a607 100644 --- a/src/include/nodes/execnodes.h +++ b/src/include/nodes/execnodes.h @@ -7,7 +7,7 @@ * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $PostgreSQL: pgsql/src/include/nodes/execnodes.h,v 1.166 2007/01/05 22:19:55 momjian Exp $ + * $PostgreSQL: pgsql/src/include/nodes/execnodes.h,v 1.167 2007/02/06 02:59:13 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -367,6 +367,16 @@ typedef struct ExecRowMark * Tuple Hash Tables * * All-in-memory tuple hash tables are used for a number of purposes. + * + * Note: tab_hash_funcs are for the key datatype(s) stored in the table, + * and tab_eq_funcs are non-cross-type equality operators for those types. + * Normally these are the only functions used, but FindTupleHashEntry() + * supports searching a hashtable using cross-data-type hashing. For that, + * the caller must supply hash functions for the LHS datatype as well as + * the cross-type equality operators to use. in_hash_funcs and cur_eq_funcs + * are set to point to the caller's function arrays while doing such a search. + * During LookupTupleHashEntry(), they point to tab_hash_funcs and + * tab_eq_funcs respectively. * ---------------------------------------------------------------- */ typedef struct TupleHashEntryData *TupleHashEntry; @@ -384,13 +394,16 @@ typedef struct TupleHashTableData HTAB *hashtab; /* underlying dynahash table */ int numCols; /* number of columns in lookup key */ AttrNumber *keyColIdx; /* attr numbers of key columns */ - FmgrInfo *eqfunctions; /* lookup data for comparison functions */ - FmgrInfo *hashfunctions; /* lookup data for hash functions */ + FmgrInfo *tab_hash_funcs; /* hash functions for table datatype(s) */ + FmgrInfo *tab_eq_funcs; /* equality functions for table datatype(s) */ MemoryContext tablecxt; /* memory context containing table */ MemoryContext tempcxt; /* context for function evaluations */ Size entrysize; /* actual size to make each hash entry */ TupleTableSlot *tableslot; /* slot for referencing table entries */ + /* The following fields are set transiently for each table search: */ TupleTableSlot *inputslot; /* current input tuple's slot */ + FmgrInfo *in_hash_funcs; /* hash functions for input datatype(s) */ + FmgrInfo *cur_eq_funcs; /* equality functions for input vs. table */ } TupleHashTableData; typedef HASH_SEQ_STATUS TupleHashIterator; @@ -585,8 +598,10 @@ typedef struct SubPlanState MemoryContext tablecxt; /* memory context containing tables */ ExprContext *innerecontext; /* working context for comparisons */ AttrNumber *keyColIdx; /* control data for hash tables */ - FmgrInfo *eqfunctions; /* comparison functions for hash tables */ - FmgrInfo *hashfunctions; /* lookup data for hash functions */ + FmgrInfo *tab_hash_funcs; /* hash functions for table datatype(s) */ + FmgrInfo *tab_eq_funcs; /* equality functions for table datatype(s) */ + FmgrInfo *lhs_hash_funcs; /* hash functions for lefthand datatype(s) */ + FmgrInfo *cur_eq_funcs; /* equality functions for LHS vs. table */ } SubPlanState; /* ---------------- |