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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2010-01-01 21:53:49 +0000 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2010-01-01 21:53:49 +0000 |
| commit | 29c4ad98293e3c5cb3fcdd413a3f4904efff8762 (patch) | |
| tree | 4e4eeea2655e87eca4d3d0dd97f3e2b7d5f1e032 /src/backend/optimizer/plan/createplan.c | |
| parent | 15faca259651c065bb20e746777f5fb9eb9d50a1 (diff) | |
| download | postgresql-29c4ad98293e3c5cb3fcdd413a3f4904efff8762.tar.gz | |
Support "x IS NOT NULL" clauses as indexscan conditions. This turns out
to be just a minor extension of the previous patch that made "x IS NULL"
indexable, because we can treat the IS NOT NULL condition as if it were
"x < NULL" or "x > NULL" (depending on the index's NULLS FIRST/LAST option),
just like IS NULL is treated like "x = NULL". Aside from any possible
usefulness in its own right, this is an important improvement for
index-optimized MAX/MIN aggregates: it is now reliably possible to get
a column's min or max value cheaply, even when there are a lot of nulls
cluttering the interesting end of the index.
Diffstat (limited to 'src/backend/optimizer/plan/createplan.c')
| -rw-r--r-- | src/backend/optimizer/plan/createplan.c | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/src/backend/optimizer/plan/createplan.c b/src/backend/optimizer/plan/createplan.c index 43b0c123ca..c8d7a28d62 100644 --- a/src/backend/optimizer/plan/createplan.c +++ b/src/backend/optimizer/plan/createplan.c @@ -10,7 +10,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/optimizer/plan/createplan.c,v 1.268 2009/12/29 20:11:45 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/optimizer/plan/createplan.c,v 1.269 2010/01/01 21:53:49 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -73,7 +73,6 @@ static MergeJoin *create_mergejoin_plan(PlannerInfo *root, MergePath *best_path, static HashJoin *create_hashjoin_plan(PlannerInfo *root, HashPath *best_path, Plan *outer_plan, Plan *inner_plan); static List *fix_indexqual_references(List *indexquals, IndexPath *index_path); -static Node *fix_indexqual_operand(Node *node, IndexOptInfo *index); static List *get_switched_clauses(List *clauses, Relids outerrelids); static List *order_qual_clauses(PlannerInfo *root, List *clauses); static void copy_path_costsize(Plan *dest, Path *src); @@ -2117,7 +2116,6 @@ fix_indexqual_references(List *indexquals, IndexPath *index_path) { NullTest *nt = (NullTest *) clause; - Assert(nt->nulltesttype == IS_NULL); nt->arg = (Expr *) fix_indexqual_operand((Node *) nt->arg, index); } @@ -2131,7 +2129,13 @@ fix_indexqual_references(List *indexquals, IndexPath *index_path) return fixed_indexquals; } -static Node * +/* + * fix_indexqual_operand + * Convert an indexqual expression to a Var referencing the index column. + * + * This is exported because planagg.c needs it. + */ +Node * fix_indexqual_operand(Node *node, IndexOptInfo *index) { /* |