Re: Crash in BRIN summarization

Heikki Linnakangas <hlinnaka(at)iki(dot)fi> writes:
> I bumped into a little bug in BRIN, while hacking on something
> unrelated. This causes a segfault, or an assertion failure if assertions
> are enabled:

Good catch.

> Fix attached.

Hm, I don't particularly care for directly comparing Datum values
like that. We don't do that elsewhere (I think) and it feels like
a type violation to me. Since you've already tested for !attbyval,
I think it'd be legitimate to extract the pointer values and compare
those, eg

if (!attr->attbyval &&
DatumGetPointer(result) != DatumGetPointer(column->bv_values[INCLUSION_UNION]))

I realize that this makes no difference in terms of the machine
code (at least for most machines?) but it avoids breaking the
Datum abstraction.

regards, tom lane