Re: Latest patches break one of our unit-test, related to RLS

On Fri, Sep 12, 2025 at 4:07 PM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> Dominique Devienne <ddevienne(at)gmail(dot)com> writes:
> >> This DOES look like a bug, no? I've done regexes for a long time,
> >> and these two forms should be equivalent IMHO. --DD
>
> Yeah, I agree it's busted. You can use EXPLAIN VERBOSE to see the
> translated-to-POSIX pattern, and it's wrong.

Thanks for confirming Tom.
And teaching me about that EXPLAIN VERBOSE trick.

I've worked-around that regression in our code, going to (x|y) instead.

What's weird is that those are still followed by _ and %,
just like [xy], so it's as-if seeing [\d\w], it stops converting
the pattern... Weird.

This misadventure kinda tells me I should maybe give up
on SIMILAR TO and just use ~, to bypass that conversion-to-POSIX...

--DD