Re: [PERFORM] auto-vacuum vs. full table update
On 04/26/2012 12:49 PM, Craig James wrote: An update to our system means I'm going to be rewriting every row of some large tables (20 million rows by 15 columns). In a situation like this, can auto-vacuum take care of it, or should I plan on vacuum-full/reindex to clean up? If you rewrite the whole table, you will end up with a table twice the size, it will not be compacted but as the table grows, the old space will be reused. jD This is 8.4.4. Thanks, Craig -- Command Prompt, Inc. - http://www.commandprompt.com/ PostgreSQL Support, Training, Professional Services and Development The PostgreSQL Conference - http://www.postgresqlconference.org/ @cmdpromptinc - @postgresconf - 509-416-6579 -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
Re: [PERFORM] auto-vacuum vs. full table update
On 04/26/2012 12:49 PM, Craig James wrote: An update to our system means I'm going to be rewriting every row of some large tables (20 million rows by 15 columns). In a situation like this, can auto-vacuum take care of it, or should I plan on vacuum-full/reindex to clean up? If you want to reclaim the space, a vacuum-full/reindex will do it. But you are probably better off using cluster. Way faster and you get new indexes as a by-product. Both methods require an exclusive lock on the table. If you can't afford the downtime, check out pg_reorg (http://pgfoundry.org/projects/reorg/) Cheers, Steve -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
Re: [PERFORM] auto-vacuum vs. full table update
Craig James cja...@emolecules.com wrote: An update to our system means I'm going to be rewriting every row of some large tables (20 million rows by 15 columns). In a situation like this, can auto-vacuum take care of it, or should I plan on vacuum-full/reindex to clean up? This is 8.4.4. If there is any way for you to update in chunks, with a vacuum after each chunk, that will prevent the extreme bloat. -Kevin -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
