On Thu, May 28, 2009 at 5:52 PM, Simon Riggs <si...@2ndquadrant.com> wrote:
> > On Thu, 2009-05-28 at 15:03 -0400, Douglas Alan wrote: > > > The application in question is a kind of data warehousing thing (of > > astronomical stars), and there's an ORM in the middle, so it's not > > easy for us to hand-tune how individual queries are specified. > > Instead, we have to structure the database and the indexes so that > > things generally perform well, without having to tweak specific > > queries. > > You should look at indexing solutions, or take professional advice on > that. I'm not sure that I know what an "indexing solution" is. > > > Users can specify fairly arbitrary search criteria. All of the > > queries should perform well. By "well", I mean within 10 seconds or > > so. > > That's an unrealistic expectation, unfortunately. Fast search requires > some form of preparatory action and without any clue as to what that > should be you cannot guarantee response times. > Unrealistic or not, it mostly currently works, modulo Postgres sometimes deciding to do a slow sequence scan when there is a perfectly good index. For instance, I just tried a query that results in 137,042 results (out of 150 million rows) is constrained in several different ways, involves a table join on another large table, and it took nine seconds. |>ouglas
