Re: ERROR: negative bitmapset member not allowed in SELECT

Alvaro Herrera <alvherre(at)2ndquadrant(dot)com> writes:
> On 2019-Jul-10, Manuel Rigger wrote:
>> CREATE TABLE t0(c0 serial, c1 boolean);
>> CREATE STATISTICS s1 ON c0, c1 FROM t0;
>> INSERT INTO t0(c1) VALUES(TRUE);
>> ANALYZE;
>> CREATE INDEX i0 ON t0(c0, (t0.c1 AND t0.c1));
>> SELECT * FROM (SELECT t0.c0 FROM t0 WHERE (((t0.c1) AND (t0.c1)) OR
>> FALSE) IS TRUE) as result WHERE result.c0 IS NULL; -- unexpected:
>> ERROR: negative bitmapset member not allowed

> Backtrace:

I'd say that mcv_get_match_bitmap has a completely misplaced level of
faith that any OpExpr it's handed will have a plain Var on one side
or the other.

Not to mention an untenable assumption that the other side is a plain
Const.

regards, tom lane