Re: Proving IS NOT NULL inference for ScalarArrayOpExpr's

From: James Coleman <jtc331(at)gmail(dot)com>
To: David Rowley <david(dot)rowley(at)2ndquadrant(dot)com>
Cc: pgsql-hackers <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: Proving IS NOT NULL inference for ScalarArrayOpExpr's
Date: 2019-01-13 19:12:38
Message-ID: CAAaqYe_2h2+Mmw2f1AFzCDo3GnUZ5sHnZrrGkv0T0xdjAu0ZRA@mail.gmail.com
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On Sat, Jan 12, 2019 at 8:52 PM David Rowley
<david(dot)rowley(at)2ndquadrant(dot)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

Attachment Content-Type Size
saop_is_not_null-v3.patch application/octet-stream 5.0 KB

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