Re: vacuum full

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: gry(at)ll(dot)mit(dot)edu
Cc: "Henrik Steffen" <steffen(at)city-map(dot)de>, pgsql-performance(at)postgresql(dot)org
Subject: Re: vacuum full
Date: 2002-11-21 19:21:24
Message-ID: 13677.1037906484@sss.pgh.pa.us
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george young <gry(at)ll(dot)mit(dot)edu> writes:
> Does someone know the right way to map from database name to
> data directory name?

pg_database.oid column.

However, that's definitely the hard way. I'd just look at the relpages
column of pg_class, which should be reasonably accurate if you've done
a VACUUM or ANALYZE recently. For example:

regression=# select relname, relkind, relpages from pg_class where
regression-# relname like 'tenk1%';
relname | relkind | relpages
---------------+---------+----------
tenk1 | r | 358
tenk1_hundred | i | 30
tenk1_unique1 | i | 30
tenk1_unique2 | i | 30
(4 rows)

Here we have a table and its three indexes, and the index sizes look
reasonable. If the index sizes approach or exceed the table size,
you are probably suffering from index bloat --- try a reindex.

regards, tom lane

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