Re: Autovacuum in the backend

Alvaro Herrera wrote:
> On Thu, Jun 16, 2005 at 04:20:34PM +1000, Gavin Sherry wrote:
>
>
>>2) By no fault of its own, autovacuum's level of granularity is the table
>>level. For people dealing with non-trivial amounts of data (and we're not
>>talking gigabytes or terabytes here), this is a serious drawback. Vacuum
>>at peak times can cause very intense IO bursts -- even with the
>>enhancements in 8.0. I don't think the solution to the problem is to give
>>users the impression that it is solved and then vacuum their tables during
>>peak periods. I cannot stress this enough.
>
>
> People running systems with petabyte-sized tables can disable autovacuum
> for those tables, and leave it running for the rest. Then they can
> schedule whatever maintenance they see fit on their gigantic tables.
> Trying to run a database with more than a dozen gigabytes of data
> without expert advice (or at least reading the manual) would be
> extremely stupid anyway.
>

professional advice won't help you here because you still have to vacuum
this giant table. this is especially critical in case of 24x7 systems
(which are quite frequent). in many cases there is no maintenance window
anymore (e.g. a wastewater system will be only 24x7).

reducing the impact of vacuum and "create index" would be important to
many people. to me improving vacuum it is as important as Jan's bgwriter
patch (it reduces the troubles people had with checkpoints).

best regards,

hans

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