On Thu, Sep 4, 2014 at 09:31:20PM +0530, Atri Sharma wrote: > I am thinking we would eventually have to cache the statistics, then get > some kind of invalidation message from the foreign server. I am also > thinking that cache would have to be global across all backends, I guess > similar to our invalidation cache. > > > > > That could lead to some bloat in storing statistics since we may have a lot of > tables for a lot of foreign servers. Also, will we have VACUUM look at > ANALYZING the foreign tables?
> Also, how will we decide that the statistics are invalid? Will we have the FDW > query the foreign server and do some sort of comparison between the statistics > the foreign server has and the statistics we locally have? I am trying to > understand how the idea of invalidation message from foreign server will work. Well, ANALYZING is running on the foreign server, and somehow it would be nice if it would send a message to us about its new statistics, or we can do it like http does and it gives us a last-refresh statistics date when we connect. I am not sure how it will work --- I am just suspecting that we might get to a point where the statistics lookup overhead on the foreign server might become a bottleneck. -- Bruce Momjian <br...@momjian.us> http://momjian.us EnterpriseDB http://enterprisedb.com + Everyone has their own god. + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
