On Wed, May 7, 2014 at 4:01 AM, Simon Riggs <si...@2ndquadrant.com> wrote: > Agreed. My proposal is that if the planner allows the lookaside to an > FDW then we pass the query for full execution on the FDW. That means > that the scan, aggregate and join could take place via the FDW. i.e. > "Custom Plan" == lookaside + FDW > > Or put another way, if we add Lookaside then we can just plug in the > pgstrom FDW directly and we're done. And everybody else's FDW will > work as well, so Citus etcc will not need to recode.
As Stephen notes downthread, Tom has already expressed opposition to this idea on other threads, and I tend to agree with him, at least to some degree. I think the drive to use foreign data wrappers for PGStrom, CitusDB, and other things that aren't really foreign data wrappers as originally conceived is a result of the fact that we've got only one interface in this area that looks remotely like something pluggable; and so everyone's trying to fit things into the constraints of that interface whether it's actually a good fit or not. Unfortunately, I think what CitusDB really wants is pluggable storage, and what PGStrom really wants is custom paths, and I don't think either of those things is the same as what FDWs provide. -- 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
