On 03/04/2011 04:54 AM, Vibhor Kumar wrote: > > On Mar 4, 2011, at 5:17 PM, Andrew Sullivan wrote: > >> On Thu, Mar 03, 2011 at 08:03:59PM -0700, Gauthier, Dave wrote: >>> Hi: >>> >>> I have to update all the records of a table. I'm worried about what the table will look like in terms of fragmentation when this is finished. Is there some sort of table healing/reorg/rebuild measure I should take if I want the resulting table to operate at optimal efficiency? What about indexes, should I drop/recreate those? >> >> Is it really important that it happen in one transaction? >> >> In the past when I've had to do this on large numbers of rows, I >> always tried to do it in batches. You can run vacuums in between >> groups, so that the table doesn't get too bloated. >> >> Otherwise, yeah, you're better off to do some of the cleanup Joshua >> suggested. >> >> A > +1 > > If UPDATE is for all rows, then > 1. CTAS with change value in SELECT > 2. Rename the tables. -- This will give zero Bloats. > Elegant, but of course, this doubles the disk space consumed. Not always tenable. -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
