On Thu, Oct 7, 2010 at 7:20 AM, Shigeru HANADA <han...@metrosystems.co.jp> wrote: > [ design for FDW ]
This seems mostly sensible. > In this step, optimizer calls FdwRoutine->GetStatistics() to get > estimated costs of the foreign scan. FDW can calculate costs by > itself with some statistics, or get costs from remote-side, or leave > the costs as is. I think this should be called EstimateCosts rather than GetStatistics. > Maybe DBAs want to see how much and what kind of connections are > established now, so we should show list of active connections via a > view or function. To treat connections transparently, I propose > that connection pooling mechanism in the core module, not in each FDW > module. Or should we add API to return list of active connections in > common format? I think for starters we should make this the responsibility of each FDW. It seems a bit hard to speculate about what we might want down the road at this point. > Should we add API which is called from ANALYZE to allow FDWs to handle > statistics when user wants. I would probably put this off also, to a later phase of the project. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
