Josh Jore <josh(at)greentechnologist(dot)org> writes:
> So I've finished reading Jeffery Friedl's _Mastering Regular Expressions_
> and while I don't need regex in PostgreSQL I know I'll do it for something
> - eventually. The book makes a distinction between DFA, POSIX NFA and
> Traditional NFA and then ascribes some properties and behaviours to each.
> So what sort does PostgreSQL have?
Well, you could read the code (src/backend/regex), or you could apply
the tests that Friedl suggests to distinguish the type of an unknown
engine ...
My guess is that it's an NFA, but I dunno if Spencer did the POSIX
semantics or not.
regards, tom lane