Thanks heaps for the advice. I will do some benchmarks to see how long it takes to cluster all of the database tables. Cheers, Jeremy -----Original Message----- From: Kevin Grittner [mailto:Kevin.Grittner@xxxxxxxxxxxx] Sent: Tuesday, 25 January 2011 1:02 p.m. To: Jeremy Palmer; Tom Lane Cc: Robert Haas; pgsql-performance@xxxxxxxxxxxxxx; andy@xxxxxxxxxxxxxxx Subject: RE: Possible to improve query plan? Jeremy Palmer <JPalmer@xxxxxxxxxxxx> wrote: > My only question is how often will I need to re-cluster the > table, because it comes at quite a cost. I probably should have mentioned that the CLUSTER will run faster if the data is already mostly in the right sequence. You'll be doing a nearly sequential pass over the heap, which should minimize seek time, especially if the OS notices the pattern and starts doing sequential read-ahead. -Kevin ______________________________________________________________________________________________________ This message contains information, which is confidential and may be subject to legal privilege. If you are not the intended recipient, you must not peruse, use, disseminate, distribute or copy this message. If you have received this message in error, please notify us immediately (Phone 0800 665 463 or info@xxxxxxxxxxxx) and destroy the original message. LINZ accepts no responsibility for changes to this email, or for any attachments, after its transmission from LINZ. Thank you. ______________________________________________________________________________________________________ -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
