On Thu, 2006-12-28 at 15:14 +0900, ITAGAKI Takahiro wrote:
> Even if it is off, DSM are always recorded and updated.
The purpose of the patch, as I understand it, is performance.
Can I ask what the performance overhead of this is for standard OLTP
workloads?
Do you have some performance numbers for VACUUM with/without this patch?
Presumably it does speed things up considerably, but question is, how
much?
Is there a point where you VACUUM more than x% of a table that it is
actually better to just VACUUM the whole thing, because of readahead?
Is there a size of table for which keeps dsm information is not
worthwhile? i.e. small tables
--
Simon Riggs
EnterpriseDB http://www.enterprisedb.com