On Thu, May 30, 2013 at 3:36 PM, Igor Neyman <iney...@perceptron.com> wrote:
> > > From: Rodrigo Barboza [mailto:rodrigombu...@gmail.com] > Sent: Thursday, May 30, 2013 2:24 PM > To: Igor Neyman > Cc: pgsql-admin@postgresql.org > Subject: Re: [ADMIN] How do I know my table is bloated? > > > I am using the defualt values for autovaccum. > How do you suggest to tune the autovacuum? > If the problem is index bloat, autovaccum won't be a solution, am I right? > > ---------------------------------------------------------- > > Rodrigo, > > I think you are putting "a cart in front of the horse" (so to speak). > Did you verify that you have bloated indexes? Under normal conditions it > shouldn't happen. > From docs (http://www.postgresql.org/docs/9.2/static/routine-reindex.html > ): > "B-tree index pages that have become completely empty are reclaimed for > re-use. However, there is still a possibility of inefficient use of space: > if all but a few index keys on a page have been deleted, the page remains > allocated. Therefore, a usage pattern in which most, but not all, keys in > each range are eventually deleted will see poor use of space." > > So, yes, if index is really gets bloated than reindexing fixes this > problem. > > Igor Neyman > Well, maybe I am. But I am worried because I know that there are some tables that do lots of updates and delete. As this concept is new for me, I am trying to be prepared to detect a situation like this.
