On Mon, 2010-07-12 at 14:57 +0100, Thom Brown wrote: > On 12 July 2010 14:50, Tom Wilcox <hungrytom@xxxxxxxxx> wrote: > > Hi Thom, > > > > I am performing update statements that are applied to a single table that is > > about 96GB in size. These updates are grouped together in a single > > transaction. This transaction runs until the machine runs out of disk space. As you are updating this table, you are leaving dead tuples behind for each of the updates that are not hot updates and the table is getting bloated. That is most likely why you are running out of disk space. Turning off fsync will not help you with this. What will help you is trying to get the database to use hot updates instead, or batching the updates and letting the table get vacuumed often enough so that the dead tuples can get marked for re-use. Hot updates would be very beneficial, even if batch updating. They will happen if their is no index on the updated column and there is enough space in the physical page to keep the tuple on the same page. You can adjust the fillfactor to try and favour this. You can check if you are doing hot updates by looking at pg_stat_user_tables for the number of hot updates. -- Brad Nicholson 416-673-4106 Database Administrator, Afilias Canada Corp. -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
