Dept of second thoughts: the IQ of estimate_array_length() needs to be

kept on par with that of scalararraysel(), else estimates that should
track might not.  Hence teach it about binary-compatible cases, too.

diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
index a56a2c24728b65c25547435285eb22e3e3e48d9b..94cb8ab6f17336e72ae5e69980c788263016c506 100644 (file)
--- a/src/backend/utils/adt/selfuncs.c
+++ b/src/backend/utils/adt/selfuncs.c
@@ -1700,6 +1700,9 @@ scalararraysel(PlannerInfo *root,
 int
 estimate_array_length(Node *arrayexpr)
 {
+       /* look through any binary-compatible relabeling of arrayexpr */
+       arrayexpr = strip_array_coercion(arrayexpr);
+
        if (arrayexpr && IsA(arrayexpr, Const))
        {
                Datum           arraydatum = ((Const *) arrayexpr)->constvalue;