From 77585bce03042e8fee62d8df0dde9c008a904699 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Fri, 21 Feb 2014 17:10:46 -0500 Subject: Do ScalarArrayOp estimation correctly when array is a stable expression. Most estimation functions apply estimate_expression_value to see if they can reduce an expression to a constant; the key difference is that it allows evaluation of stable as well as immutable functions in hopes of ending up with a simple Const node. scalararraysel didn't get the memo though, and neither did gincost_opexpr/gincost_scalararrayopexpr. Fix that, and remove a now-unnecessary estimate_expression_value step in the subsidiary function scalararraysel_containment. Per complaint from Alexey Klyukin. Back-patch to 9.3. The problem goes back further, but I'm hesitant to change estimation behavior in long-stable release branches. --- src/backend/utils/adt/array_selfuncs.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) (limited to 'src/backend/utils/adt/array_selfuncs.c') diff --git a/src/backend/utils/adt/array_selfuncs.c b/src/backend/utils/adt/array_selfuncs.c index e35edf8ec84..20eb358a620 100644 --- a/src/backend/utils/adt/array_selfuncs.c +++ b/src/backend/utils/adt/array_selfuncs.c @@ -68,11 +68,13 @@ static int float_compare_desc(const void *key1, const void *key2); * scalararraysel_containment * Estimate selectivity of ScalarArrayOpExpr via array containment. * - * scalararraysel() has already verified that the operator of a - * ScalarArrayOpExpr is the array element type's default equality or - * inequality operator. If we have const =/<> ANY/ALL (array_var) - * then we can estimate the selectivity as though this were an array - * containment operator, array_var op ARRAY[const]. + * If we have const =/<> ANY/ALL (array_var) then we can estimate the + * selectivity as though this were an array containment operator, + * array_var op ARRAY[const]. + * + * scalararraysel() has already verified that the ScalarArrayOpExpr's operator + * is the array element type's default equality or inequality operator, and + * has aggressively simplified both inputs to constants. * * Returns selectivity (0..1), or -1 if we fail to estimate selectivity. */ @@ -99,9 +101,8 @@ scalararraysel_containment(PlannerInfo *root, } /* - * Aggressively reduce leftop to a constant, if possible. + * leftop must be a constant, else punt. */ - leftop = estimate_expression_value(root, leftop); if (!IsA(leftop, Const)) { ReleaseVariableStats(vardata); -- cgit v1.2.3