On Thu, Dec 1, 2016 at 9:45 AM, xu jian <jamesxu@outlook.com> wrote:
> Thanks for your reply. Is there any reason to update index
> statistics even if there is no changes on the table?
> or is there any way to disable index statistics update during vacuum freeze?
> thanks
I think that the indexes only need to be scanned if the VACUUM finds
dead tuples. But even 1 dead tuple will cause a complete scan of
every index. I've complained about this before and I think there's
room for improvement here, but nobody's been motivated enough to
pursue this yet.
--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company