On Wed, 13 Nov 2002, Williams, Travis L, NPONS wrote:
> I thought reindexing was only to be used on corrupt tables.. will
> vacumming fix the problem?
No, unfortunately, for certain classes of problems such as 'update table
set field2=field2+1' kind of things, where huge amounts of a table are
updated at once, it appears that the deleted space in an index may not be
reclaimed, and the only way to get it back is to drop and recreate the
index. Reindex is just one of the easier ways to drop and recreate and
index. You could always do it in SQL as well. Note that pg_indexes
contains all the information needed to recreate an index (i.e. it has the
exact sql used to create an index stored away) so you could theoretically
use that table to recreate your indexes as well.