Message-ID: <48E10C95.2050207@pinpointresearch.com>
Date: Mon, 29 Sep 2008 10:12:53 -0700
From: Steve Crawford <scrawford@pinpointresearch.com>
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To: Peter Kovacs <maxottovonstirlitz@gmail.com>
CC: Tom Lane <tgl@sss.pgh.pa.us>, pgsql-admin@postgresql.org
Subject: Re: Do we need vacuuming when tables are regularly dropped?
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	<9815.1222690583@sss.pgh.pa.us>
	<b6e8f2e80809290533g2a7e09b1i110bb085ad75092e@mail.gmail.com>
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>> What it sounds like to me is that you're not vacuuming the system
>> catalogs, which are getting bloated with dead rows about all those
>> dropped tables.
>>     
>
> Wow, great!
>
> It is not immediately clear from the documentation, but the VACUUM
> command also deals with the system catalogs as well, correct?
>
>   

To expand on Tom's answer, rows in system tables are created not only 
for tables but for each column in the table, rules, indexes, etc. You  
can end up with a lot more row creation than you suspect. And temporary 
tables bloat the system tables just like regular tables. We discovered 
that cron scripts using temporary tables can cause very rapid 
system-table blotage.

Cheers,
Steve