diff options
Diffstat (limited to 'src/backend/optimizer/util/clauses.c')
| -rw-r--r-- | src/backend/optimizer/util/clauses.c | 29 |
1 files changed, 28 insertions, 1 deletions
diff --git a/src/backend/optimizer/util/clauses.c b/src/backend/optimizer/util/clauses.c index 14b9313a9a..c826ecb2ad 100644 --- a/src/backend/optimizer/util/clauses.c +++ b/src/backend/optimizer/util/clauses.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/optimizer/util/clauses.c,v 1.269 2008/10/09 19:27:40 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/optimizer/util/clauses.c,v 1.270 2008/10/21 20:42:53 tgl Exp $ * * HISTORY * AUTHOR DATE MAJOR EVENT @@ -1188,6 +1188,12 @@ find_nonnullable_rels_walker(Node *node, bool top_level) result = find_nonnullable_rels_walker((Node *) expr->quals, top_level); } + else if (IsA(node, PlaceHolderVar)) + { + PlaceHolderVar *phv = (PlaceHolderVar *) node; + + result = find_nonnullable_rels_walker((Node *) phv->phexpr, top_level); + } return result; } @@ -1393,6 +1399,12 @@ find_nonnullable_vars_walker(Node *node, bool top_level) result = find_nonnullable_vars_walker((Node *) expr->quals, top_level); } + else if (IsA(node, PlaceHolderVar)) + { + PlaceHolderVar *phv = (PlaceHolderVar *) node; + + result = find_nonnullable_vars_walker((Node *) phv->phexpr, top_level); + } return result; } @@ -1921,6 +1933,7 @@ eval_const_expressions(PlannerInfo *root, Node *node) * constant. This effectively means that we plan using the first supplied * value of the Param. * 2. Fold stable, as well as immutable, functions to constants. + * 3. Reduce PlaceHolderVar nodes to their contained expressions. *-------------------- */ Node * @@ -2823,6 +2836,20 @@ eval_const_expressions_mutator(Node *node, newfslink->quals = quals; return (Node *) newfslink; } + if (IsA(node, PlaceHolderVar) && context->estimate) + { + /* + * In estimation mode, just strip the PlaceHolderVar node altogether; + * this amounts to estimating that the contained value won't be forced + * to null by an outer join. In regular mode we just use the default + * behavior (ie, simplify the expression but leave the PlaceHolderVar + * node intact). + */ + PlaceHolderVar *phv = (PlaceHolderVar *) node; + + return eval_const_expressions_mutator((Node *) phv->phexpr, + context); + } /* * For any node type not handled above, we recurse using |