In an attempt to throw the authorities off his trail, clapidus@hotmail.com ("Claudio Lapidus") transmitted:
>> Run VACUUM VERBOSE on it; you'll no doubt see that some internal
>> tables such as pg_activity, pg_statistic, and such have a lot of dead
>> tuples. Establishing a connection leads to _some_ DB activity, and
>> probably a dead tuple or two; every time you ANALYZE, you create a
>> bunch of dead tuples since old statistics are "killed off."
>
> What? Does this mean that it is needed to routinely vacuum system tables
> too? If so, which is the recommended procedure?
On some 7.2 systems I work with, a smattering of system tables are
vacuumed hourly along with applications that are known to be good
"fodder" for the purpose.
In 7.3 and 7.4, the "contrib" application, pg_autovacuum can do the
trick, vacuuming anything that reaches thresholds of
inserts/deletes/updates, and do so more or less as often as necessary.
If you haven't got a cron job looking something like:
0 0 * * * * vacuumdb -a -z > /dev/null 2> /dev/null
then you should probably add that, at least.
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