Message-ID: <4315B5EF.5020509@ca.afilias.info>
Date: Wed, 31 Aug 2005 09:51:43 -0400
From: Brad Nicholson <bnichols@ca.afilias.info>
User-Agent: Mozilla Thunderbird 0.8 (X11/20040913)
MIME-Version: 1.0
To: pgsql-performance@postgresql.org
Subject: Re: 'Real' auto vacuum?
References: <4314DBE0.9070708@telogis.com>
	<200508301558.34697.josh@agliodbs.com>
	<00f601c5adeb$56fcb910$f20214ac@bite.lt>
In-Reply-To: <00f601c5adeb$56fcb910$f20214ac@bite.lt>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit

Mindaugas Riauba wrote:

>>>When a row is orphaned it's added to a list of possibly available rows.
>>>When a new row is needed the list of possible rows is examined and the
>>>first one with a transaction id less then the lowest running transaction
>>>id is chosen to be the new row?  These rows can be in a heap so it's
>>>really fast to find one.
>>>      
>>>
>>This is the long-term plan.    However, it's actually a lot harder than it
>>sounds.  Patches welcome.
>>    
>>
>
>  Some ETA? Since that would be the most welcome addition for us. We
>have few very heavily updated databases where table bloat and constant
>vacuuming is killing performance.
>
> 
>
How often are you vacuuming (the definition of 'constantly' tends to 
vary)?  Are you vacuuming the whole database each time?  If so, identify 
which tables are being updated frequently, and vacuum those often.  
Vacuum other tables less frequently.

Also, are you you using VACUUM FULL (if so, you certainly don't want to be).

-- 
Brad Nicholson  416-673-4106    bnichols@ca.afilias.info
Database Administrator, Afilias Canada Corp.