Re: Foreground vacuum and buffer access strategy

On Fri, May 25, 2012 at 4:06 PM, Jeff Janes <jeff.janes@gmail.com> wrote:
> If I invoke vacuum manually and do so with VacuumCostDelay == 0, I
> have basically declared my intentions to get this pain over with as
> fast as possible even if it might interfere with other processes.
>
> Under that condition, shouldn't it use BAS_BULKWRITE rather than
> BAS_VACUUM?  The smaller ring size leads to a lot of synchronous WAL
> flushes which I think can slow the vacuum down a lot.

Of course, an autovacuum of a really big table could run too slowly,
too, even though it's not a foreground task.

--
Robert Haas
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