Re: Rules of Thumb for Autovaccum

Thanks. What about auto-analyze? When will they be analyzed by default?
And what actions generally require new analyze?

On 2/15/12, Bruce Momjian <bruce(at)momjian(dot)us> wrote:
> On Wed, Feb 15, 2012 at 09:14:34AM -0500, Robert James wrote:
>> What rules of thumb exist for:
>> * How often a table needs to be vacuumed?
>> * How often a table needs to be analyzed?
>> * How to tune Autovacuum?
>>
>> I have a large DB server, and I'm concerned that it's not being
>> autovaccumed and autoanalyzed frequently enough. But I have no idea
>> what proper values should be?
>>
>> A related question: If I INSERT a large number of records per day,
>> similar in nature to the existing records, does that require new
>> vacuum? new analyze? Or do I only need those for DELETEs or changes to
>> the nature of records?
>>
>> Finally: What type of performance impact can I expect from vacuum and
>> analyze, in general?
>
> Unless you are very high-volume, the auto-vacuum default settings are
> fine. The default do allow up to 20% of unused space in tables, but
> making that lower is expensive to performance.
>
> --
> Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
> EnterpriseDB http://enterprisedb.com
>
> + It's impossible for everything to be true. +
>