Re: [sqlsmith] Crash in mcv_get_match_bitmap - Mailing list pgsql-hackers

Andreas Seltenreich <seltenreich@gmx.de> writes:
> running sqlsmith on the regression database of REL_12_STABLE at
> ff597b656f yielded a crash in mcv_get_match_bitmap.  I can reproduce it
> with the following query on the regression database:
>     select filler1 from mcv_lists where a is not null and (select 42) <= c;

Seems to be the same problem I just complained of in the other
thread: mcv_get_match_bitmap has an untenable assumption that
"is a pseudoconstant" means "is a Const".

I notice it's also assuming that the Const must be non-null.
It's not really easy to crash it that way, because if you just
write "null <= c" that'll get reduced to constant-NULL earlier.
But I bet there's a way.

            regards, tom lane