Re: Notes about fixing regexes and UTF-8 (yet again)

Dimitri Fontaine <dimitri(at)2ndQuadrant(dot)fr> writes:
> Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> writes:
>> Yeah, it's conceivable that we could implement something whereby
>> characters with codes above some cutoff point are handled via runtime
>> calls to iswalpha() and friends, rather than being included in the
>> statically-constructed DFA maps. The cutoff point could likely be a lot
>> less than U+FFFF, too, thereby saving storage and map build time all
>> round.

> It's been proposed to build a regexp type in PostgreSQL which would
> store the DFA directly and provides some way to run that DFA out of its
> storage without recompiling.

> Would such a mechanism be useful here?

No, this is about what goes into the DFA representation in the first
place, not about how we store it and reuse it.

regards, tom lane