Re: Proving IS NOT NULL inference for ScalarArrayOpExpr's

On Sat, Jan 12, 2019 at 8:52 PM David Rowley
<david.rowley@2ndquadrant.com> wrote:
>
> Basically, the planner assumes that the WHERE a IS NOT NULL index
> implies WHERE b IN(1,...,101), which is definitely not the case.
>
> Probably your new code needs to be expanded to become:
>
> if (IsA(clause, ScalarArrayOpExpr))
> {
>     ScalarArrayOpExpr *saop = (ScalarArrayOpExpr *) clause;
>     if (op_strict(saop->opno) &&
>         clause_is_strict_for((Node *) linitial(saop->args), subexpr))
>         return true;
> }

I've updated the code as well as included the sad path test in
addition to my original happy path test.

Patch v3 attached.

James Coleman