matshyeq <matshyeq@gmail.com> writes:
> I can see postgresql claims to supports regular expression flags:
Yup.
> What I find don't makes sense to me is that those flags could be used to
> switch on/off match feature locally as opposed to the whole regex (same as
> though flags parameters of regex functions).
Not all of them would make sense locally; in fact I'd venture that
case-sensitivity is the *only* flag that anyone would consider using
that way.
> Perl supports that locality while postgres documentation says:
> "*An ARE can begin with embedded options: a sequence (?xyz) (where xyz is
> one or more alphabetic characters) specifies options affecting the rest of
> the RE.
Right. It says "begin with" and it means "begin with".
We are not Perl and are not attempting to be bug-compatible with its regex
engine. If you want bug-compatibility, see PL/Perl.
regards, tom lane
