Re: [GENERAL] Autovacuum Improvements

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>
To: Bruce Momjian <bruce@momjian.us>
Cc: "Jim C. Nasby" <jim@nasby.net>, Ron Mayer <rm_pg@cheapcomplexdevices.com>, Gregory Stark <stark@enterprisedb.com>, pgsql-hackers@postgresql.org
Date: 2007-01-26T04:13:20Z
Lists: pgsql-hackers
Bruce Momjian <bruce@momjian.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.

			regards, tom lane