Re: Feature proposal: www_fdw

2011/9/29 Florian Pflug <fgp(at)phlo(dot)org>:
> You could use a hash table, allocated in the top-level memory context,
> to store one authentication token per combination of server and local user.

In fact I started something in this way, with ldap_fdw, stashing the
connection away using memory context and something using es_query_cxt
from EState, just testing until now. How do this from PlanForeignScan
I couldn't figure out yet.

> I suggest you look at the MySQL FDW (https://github.com/dpage/mysql_fdw)
> - they presumably re-use the same connection over multiple foreign scans,
> which seems to be a problem similar to yours.

From what I understand they re-use between BeginForeignScan and the
subsequent IterateForeignScans and freeing at end. In my tests, there
is a (re)connection for each SELECT * FROM ...

I'm wondering that would be nice to have some built-in facilities
(like this kind of "cache" between calls) provided by www_fdw, for
that WWW API based FDWs.

Regards.
--
Dickson S. Guedes
mail/xmpp: guedes(at)guedesoft(dot)net - skype: guediz
http://guedesoft.net - http://www.postgresql.org.br