On Wed, Aug 4, 2010 at 7:00 PM, Tom Lane <t...@sss.pgh.pa.us> wrote: > Merlin Moncure <mmonc...@gmail.com> writes: >> While chatting with Haas off-list regarding how the new array/string >> functions should work (see the thread in its glory here: >> http://www.mail-archive.com/pgsql-hackers@postgresql.org/msg148865.html) >> the debate morphed into the relative pros and cons about the proposed >> concat() being marked stable vs immutable. I did some checking into >> how things work now, and found some surprising cases. > > Er ... "now" being defined as what? I can't replicate your results in > HEAD. In particular, textanycat isn't immutable anymore.
ah, my mistake. I'm using a fairly old build of 9.0. > The DROP CAST case is a bit interesting. We don't record a dependency > on the cast as such, but on the underlying function --- if you'd tried > to drop the function you'd not have been allowed to. It is a bit > peculiar that dropping the cast causes the meaning of a::text to change, > but I'm not sure there's much we can do about that. In any case, it > seems like that's not nearly as much of a hazard as doing CREATE OR > REPLACE FUNCTION and changing the computation done by the function. > We could disallow that maybe, but that cure seems worse than the > disease. yep (the textanycat was much more interesting to me) merlin -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers