On Thu, Apr 21, 2011 at 4:05 AM, Brendan Jurd <direvus@xxxxxxxxx> wrote: > > "IMMUTABLE indicates that the function cannot modify the database and > always returns the same result when given the same argument values" > > Emphasis on "always". If the result of the function, given the same > argument values, can be different after a SET, then it doesn't qualify > for immutability. At least, that's my understanding. That's a ridiculous use of the word "Immutable" In any CS class, the timezone would be an implicit input to the function. So it would be immutable in *that* sense (it also takes timezone into consideration). Perhaps the optimizer should take contextual information that cannot change inside a query as input too. -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
