Thomas Munro wrote: > I am using 9.1.6, and I've set up a partitioned table as described in the manual, with partitions > based on a timestamptz column called 'time'. The exclusion constraints work nicely when I select > ranges of times with literal constants. But why would a WHERE clause like the following not benefit > from exclusion constraints? > > time > TIMESTAMPTZ '2012-11-03 00:00:00Z' + INTERVAL '24 hours' > > > Isn't that expression on the right reducible to a constant up front? Obviously I can use a host > language to do the arithmetic and provide a constant, but I am curious to understand why that wouldn't > be constant-folded.
I think the problem is that this + operator is implemented by the function "timestamptz_pl_interval", which is STABLE but not IMMUTABLE. I am not sure why this function cannot be IMMUTABLE, it seems to me that it should be. Yours, Laurenz Albe -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
