On Thu, Apr 16, 2009 at 9:49 AM, Tom Lane <tgl@xxxxxxxxxxxxx> wrote: > Merlin Moncure <mmoncure@xxxxxxxxx> writes: >> On Thu, Apr 16, 2009 at 8:05 AM, Matthew Wakeling <matthew@xxxxxxxxxxx> wrote: >>> That solves the problem. So, a view is treated as a subquery then? > >> no...the view is simply inlined into the query (think C macro) using >> the rules. You just bumped into an arbitrary (and probably too low) >> limit into the number of tables the planner can look at in terms of >> optimizing certain types of plans. > > Bear in mind that those limits exist to keep you from running into > exponentially increasing planning time when the size of a planning > problem gets big. "Raise 'em to the moon" isn't really a sane strategy. > It might be that we could get away with raising them by one or two given > the general improvement in hardware since the values were last looked > at; but I'd be hesitant to push the defaults further than that. I hasten to point out that I only suggested raising them to the moon as a DEBUGGING strategy, not a production configuration. I do however suspect that raising the defaults would be a good idea. It seems that the limit has been 8 since those parameters were added back in January of 2003, and yes, hardware is a lot better now. We should probably raise geqo_threshold at the same time, since that's supposed to be larger than these parameters and the default is only 12. ...Robert -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
