On Wed, Jun 30, 2010 at 6:57 PM, Tom Lane <t...@sss.pgh.pa.us> wrote: > Peter Eisentraut <pete...@gmx.net> writes: >> <kibo> >> "The <search condition> shall simply contain a <boolean value >> expression> that is retrospectively deterministic." > >> This is then defined in a rather complex manner that ends up disallowing >> col > now() but allowing col < now(). >> </kibo> > > Oh, cute. Seems to have been added in SQL:2003. I guess somebody > nagged them about wanting to be able to write CHECK(col <= now()). > The detailed definition is amazingly laborious and yet limited, though, > as it basically doesn't address the problem except for that specific > case and close relatives.
Well, solving the problem in general is equivalent to the halting problem, so... -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise Postgres Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
