Re: Supporting = operator in gin/gist_trgm_ops

Julien Rouhaud <rjuju123(at)gmail(dot)com> writes:
> On Mon, Oct 26, 2020 at 5:03 AM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>> I think you may be overoptimistic about being able to use the identical
>> code path without regard for LIKE wildcards; but certainly it should be
>> possible to do this with not a lot of new code. +1.

> Well, that's what I was thinking too, but I tried all the possible
> wildcard combinations I could think of and I couldn't find any case
> yielding wrong results. As far as I can see the index scans return at
> least all the required rows, and all extraneous rows are correctly
> removed either by heap recheck or index recheck.

But "does it get the right answers" isn't the only figure of merit.
If the index scan visits far more rows than necessary, that's bad.
Maybe it's OK given that we only make trigrams from alphanumerics,
but I'm not quite sure.

regards, tom lane