On Sun, Apr 3, 2011 at 5:38 PM, Tom Lane <t...@sss.pgh.pa.us> wrote: > Dave Page <dp...@pgadmin.org> writes: >> I can't help thinking I must be missing something obvious here, but is >> there any way to persist some data from PlanForeignScan to at least >> BeginForeignScan in an FDW? I'm aware of fdwplan->fdw_private, but at >> that needs to be copyObject compatible, it's not much use to me. > >> The issue I have is that in order to properly plan my remote scan, I >> need to connect to the remote database to try to calculate some stats >> for the query. I'm currently then disconnecting and freeing all the >> data associated with that connection, and then reconnecting again in >> BeginForeignScan in order to do the actual work. I'd like to avoid the >> connect/reconnect, as we all know they can be expensive! > > I'd suggest that you reference your open connections with an integer > index, which you could then store in the plan node. Plans don't have to > survive longer than the current backend, so this would be perfectly safe > so long as you don't re-use the indexes within a session. > > Or you could use a hash of some other identifying information (perhaps > the OID of the foreign server would be sufficient ID for a connection?).
Ahh, ok - that should work. Thanks! -- Dave Page Blog: http://pgsnake.blogspot.com Twitter: @pgsnake EnterpriseDB UK: 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
