Craig Ringer <craig@postnewspapers.com.au> writes:
> I do think this comes up often enough that a built-in trigger "update
> named column with result of expression on insert" trigger might be
> desirable.
There's something of the sort in contrib already, I believe, though
it's so old it still uses abstime :-(
> So might "CREATE LANGUAGE ... IF NOT EXISTS". Maybe even "CREATE ROLE
> ... IF NOT EXISTS" and "CREATE USER ... IF NOT EXISTS" - I know I'd find
> them really handy.
CREATE IF NOT EXISTS has been proposed and rejected before, more than
once. Please see the archives.
regards, tom lane