On Fri, Sep 12, 2025 at 4:07 PM Tom Lane <[email protected]> wrote: > Dominique Devienne <[email protected]> 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
