Re: PostgreSQL Gotchas

Chris Travers <chris@travelamericas.com> writes:
> Any chance of adding a configuration option for future versions in order
> to set case folding behavior?  It seems that PostgreSQL has really
> attempted to be as standards-compliant as possible and this is one area
> where improvement could be made without breaking backward compatibility...

Fixing the case issue is not *anywhere* near that easy.  See past discussions.

>> http://archives.postgresql.org/pgsql-general/2004-11/msg01375.php
>> and the "previous discussion" referred to is this thread:
>> http://archives.postgresql.org/pgsql-hackers/2004-10/msg00082.php
>>
>> As you can see, there wasn't a lot of agreement that we ought to change
>> it.  Arguably, if we did change it we'd get ripped for the "gotcha" of
>> poor optimization when the user forgets to mark nonvolatile functions
>> properly.  (Personally, though, I'm in favor of tightening it up.)
>
> It all depends on which is worse?  Incorrect results or bad performance
> on poorly written functions?  I would side with bad performance any day
> if it was user error and could be fixed with the help of the people on
> the PERFORM list.

Well, as I said, I'm personally in favor of tightening up the
query-flattening rules, but that will not in itself make volatile
functions in subselects 100% gotcha-free.

            regards, tom lane