Kieren Scott <kierenscott@xxxxxxxxxxx> wrote: > I'm trying to understand what is going on internally when doing a > VACUUM FULL on a table in 8.3. > > I have a table that is 1GB in size, 500M is used, and 500M is free > space. When I do a vacuum full on this table, will it either: - > > 1) Compact all of the used tuples into free space within the > existing disk file and then shrink the file to 500M. Therefore > simply freeing up 500M in the disk file. On 8.3, this is what it will do, although it can take a very long time. I've given up on this before completion (sometimes after leaving it cranking away for a couple days) every time I've tried it on a table with more than a few GB and any significant bloat. I don't know that I've ever tried it on a table as small as you describe, but I would bet that CLUSTER is going to be much faster if you have the half a GB free space. Another issue with VACUUM FULL is that it bloats indexes; so you generally need to follow it with a REINDEX on the table. -Kevin -- Sent via pgsql-admin mailing list (pgsql-admin@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-admin
