On 17-12-2014 AM 12:15, Robert Haas wrote: > On Mon, Dec 15, 2014 at 6:55 PM, Amit Langote > <langote_amit...@lab.ntt.co.jp> wrote: >> Robert wrote: >>> I would expect that to fail, just as it would fail if you tried to >>> build an index using a volatile expression. >> >> Oops, wrong example, sorry. In case of an otherwise good expression? > > I'm not really sure what you are getting here. An "otherwise-good > expression" basically means a constant. Index expressions have to be > things that always produce the same result given the same input, > because otherwise you might get a different result when searching the > index than you did when building it, and then you would fail to find > keys that are actually present. In the same way, partition boundaries > also need to be constants. Maybe you could allow expressions that can > be constant-folded, but that's about it.
Yeah, this is what I meant. Expressions that can be constant-folded. Sorry, the example I chose was pretty lame. I was just thinking about kind of stuff that something like pg_node_tree would be a good choice for as on-disk representation of partition values. Though definitely it wouldn't be to store arbitrary expressions that evaluate to different values at different times. Thanks, Amit -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers