Re: [GENERAL] Autovacuum Improvements

Tom Lane wrote:
> Bruce Momjian <bruce(at)momjian(dot)us> writes:
> > Jim C. Nasby wrote:
> >> If we extended relations by more than one page at a time we'd probably
> >> have a better shot at the blocks on disk being contiguous and all read
> >> at the same time by the OS.
>
> > Actually, there is evidence that adding only a single page to the end
> > causes a lot of contention for that last page, and that adding a few
> > might be better.
>
> Evidence where? The code is designed so that the last page *isn't*
> shared --- go read the comments in hio.c sometime.

I was talking about the last page of a table, where INSERTs all cluster
on that last page and cause lots of page locking. hio.c does look like
it avoids that problem.

--
Bruce Momjian bruce(at)momjian(dot)us
EnterpriseDB http://www.enterprisedb.com

+ If your life is a hard drive, Christ can be your backup. +