On 07/02/2014 11:10 AM, Noah Misch wrote: > On Tue, Jul 01, 2014 at 11:49:43AM +0800, Craig Ringer wrote: >> Currently it's unsafe/not possible to use some funtions, like >> date_trunc, in immutable functions and expression indexes. >> >> It'd be really useful to have an immutable version that took the >> timezone as an argument. Maybe this is a worthwhile beginner TODO item >> for the wiki? >> >> I'm sure there are other funcs that could use TimeZone-insensitive >> variants too. > > You can achieve it today with the AT TIME ZONE operator: > > CREATE INDEX ON t ((date_trunc('week', col_name AT TIME ZONE > 'Asia/Macau'))); > > If "version of date_part having a timezone argument" is the desired interface, > one can wrap that idiom in a one-line SQL function. I doubt adding such a > wrapper to core is worth the weight.
I think it'd be a usability boost, but given the example above, probably not worth the effort. Thanks for pointing that out - useful one for the archives. -- Craig Ringer http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers