On 02/25/2015 07:15 PM, Amit Langote wrote: > On 26-02-2015 AM 05:15, Josh Berkus wrote: >> On 02/24/2015 12:13 AM, Amit Langote wrote: >>> Here is an experimental patch that attempts to implement this. >> >> This looks awesome. > > Thanks! > >> I would love to have it for 9.5, but I guess the >> patch isn't nearly baked enough for that? >> > > I'm not quite sure what would qualify as baked enough for 9.5 though we > can surely try to reach some consensus on various implementation aspects > and perhaps even get it ready in time for 9.5.
Well, we don't have long at all to do that. I guess I'm asking what kind of completeness of code we have; is this basically done pending API changes and bugs, or are there major bits (like, say, pg_dump and EXPLAIN support) which are completely unimplemented? >>> where key_spec consists of partition key column names and optional >>> operator class per column. Currently, there are restrictions on the >>> key_spec such as allowing only column names (not arbitrary expressions >>> of them), only one column for list strategy, etc. >> >> What's the obstacle to supporting expressions and/or IMMUTABLE >> functions? I think it's fine to add this feature without them >> initially, I'm just asking about the roadmap for eventually supporting >> expressions in the key spec. >> > > Only one concern I can remember someone had raised is that having to > evaluate an expression for every row during bulk-inserts may end up > being pretty expensive. Though, we might have to live with that. Well, it's not more expensive than having to materialize the value from a trigger and store it on disk. The leading one here would be functions over timestamp; for example, the data has a timestamptz, but you want to partition by week. > > I think one idea is to learn from ability to use expressions in indexes. Sure. So a feature to implement for the 2nd release. -- Josh Berkus PostgreSQL Experts Inc. http://pgexperts.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
