On Thu, Feb 3, 2011 at 7:41 AM, Kenneth Marshall <ktm@xxxxxxxx> wrote: > On Thu, Feb 03, 2011 at 02:11:58AM -0800, david@xxxxxxx wrote: >> On Thu, 3 Feb 2011, Vitalii Tymchyshyn wrote: >> >>> 02.02.11 20:32, Robert Haas ???????(??): >>>> Yeah. ÂAny kind of bulk load into an empty table can be a problem, >>>> even if it's not temporary. ÂWhen you load a bunch of data and then >>>> immediately plan a query against it, autoanalyze hasn't had a chance >>>> to do its thing yet, so sometimes you get a lousy plan. >>> >>> May be introducing something like 'AutoAnalyze' threshold will help? I >>> mean that any insert/update/delete statement that changes more then x% of >>> table (and no less then y records) must do analyze right after it was >>> finished. >>> Defaults like x=50 y=10000 should be quite good as for me. >> >> If I am understanding things correctly, a full Analyze is going over all >> the data in the table to figure out patterns. >> >> If this is the case, wouldn't it make sense in the situation where you are >> loading an entire table from scratch to run the Analyze as you are >> processing the data? If you don't want to slow down the main thread that's >> inserting the data, you could copy the data to a second thread and do the >> analysis while it's still in RAM rather than having to read it off of disk >> afterwords. >> >> this doesn't make sense for updates to existing databases, but the use case >> of loading a bunch of data and then querying it right away isn't _that_ >> uncommon. >> >> David Lang >> > > +1 for in-flight ANALYZE. This would be great for bulk loads of > real tables as well as temp tables. Yes, please, that would be really nice. -- Jon -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
