Re: Inefficient nbtree behavior with row-comparison quals

Peter Geoghegan <pg@bowt.ie> writes:
> On Sat, May 11, 2024 at 4:21 PM Tom Lane <tgl@sss.pgh.pa.us> wrote:
>>> There's another problem along these lines, that seems at least as bad:
>>> queries involving contradictory >= and <= quals aren't recognized as
>>> contradictory during preprocessing. There's no reason why
>>> _bt_preprocessing_keys couldn't detect that case; it just doesn't
>>> right now.

>> Ugh, how'd we miss that?  I can take a look at this, unless you're
>> on it already.

> My draft skip scan/MDAM patch already deals with this in passing. So
> you could say that I was already working on this. But I'm not sure
> that I would actually say so myself; what I'm doing is tied to far
> more complicated work.

Hmm, I'm generally in favor of a lot of small patches rather than one
enormously complex one.  Isn't this point something that could be
broken out?

            regards, tom lane