Re: A qsort template

Hi,

On 2022-04-03 17:46:28 +1200, Thomas Munro wrote:
> On Sun, Apr 3, 2022 at 11:11 AM Andres Freund <andres(at)anarazel(dot)de> wrote:
> > On 2022-04-03 09:45:13 +1200, Thomas Munro wrote:
> > > I think we just need to decide up front if we're in a situation that
> > > can't provide datum1/isnull1 (in this case because it's an expression
> > > index), and skip the optimised paths. Here's an experimental patch...
> > > still looking into whether there are more cases like this...
>
> I didn't find anything else.
>
> Maybe it'd be better if we explicitly declared whether datum1 is used
> in each tuplesort mode's 'begin' function, right next to the code that
> installs the set of routines that are in control of that? Trying that
> in this version. Is it clearer what's going on like this?

Seems an improvement.

> > I'm a bit worried that none of the !ubsan tests failed on this...
>
> In accordance with whoever-it-was-that-said-that's law about things
> that aren't tested, this are turned out to be broken already[1].

Yea :/.

Would be good to get this committed soon, so we can see further ubsan
violations introduced in the next few days (and so I can unblock my local dev
tests :P).

Greetings,

Andres Freund