Simon Riggs <si...@2ndquadrant.com> writes: > On 5 March 2013 22:02, Tom Lane <t...@sss.pgh.pa.us> wrote: >> FWIW, my opinion is that doing anything like this in the planner is >> going to be enormously expensive.
> As we already said: no MVs => zero overhead => no problem. Well, in the first place that statement is false on its face: we'll still spend cycles looking for relevant MVs, or at least maintaining a complexly-indexed cache that helps us find out that there are none in a reasonable amount of time. In the second place, even if it were approximately true it wouldn't help the people who were using MVs. > It costs in > the cases where time savings are possible and not otherwise. And that is just complete nonsense: matching costs whether you find a match or not. Could we have a little less Pollyanna-ish optimism and a bit more realism about the likely cost of such a feature? regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers