Re: Missing update of all_hasnulls in BRIN opclasses

On 2023-Apr-24, Tomas Vondra wrote:

> On 4/24/23 17:36, Alvaro Herrera wrote:

> > (As for your FIXME comment in brin_memtuple_initialize, I think you're
> > correct: we definitely need to reset bt_placeholder. Otherwise, we risk
> > places that call it in a loop using a BrinMemTuple with one range with
> > the flag set, in a range where that doesn't hold. It might be
> > impossible for this to happen, given how narrow the conditions are on
> > which bt_placeholder is used; but it seems safer to reset it anyway.)
>
> Yeah. But isn't that a separate preexisting issue, strictly speaking?

Yes.

> > I did a quick experiment of turning the patches over -- applying test
> > first, code fix after (requires some conflict fixing). With that I
> > verified that the behavior of 'hasnulls' indeed changes with the code
> > fix.
>
> Thanks. Could you do some testing of the union_tuples stuff too? It's a
> bit tricky part - the behavior is timing sensitive, so testing it
> requires gdb breakpoints breakpoints or something like that. I think
> it's correct, but it'd be nice to check that.

I'll have a look.

--
Álvaro Herrera Breisgau, Deutschland — https://www.EnterpriseDB.com/
<inflex> really, I see PHP as like a strange amalgamation of C, Perl, Shell
<crab> inflex: you know that "amalgam" means "mixture with mercury",
more or less, right?
<crab> i.e., "deadly poison"