On 16 August 2016 at 19:46, Andres Freund <andres@anarazel.de> wrote: > On 2016-08-15 12:02:18 -0400, Robert Haas wrote: >> Thanks for taking a stab at this. I'd like to throw out a few concerns. >> >> One, I'm worried that adding an additional layer of pointer-jumping is >> going to slow things down and make Andres' work to speed up the >> executor more difficult. I don't know that there is a problem there, >> and if there is a problem I don't know what to do about it, but I >> think it's something we need to consider. > > I'm quite concerned about that as well.
This objection would apply to all other proposals as well, FDW etc..
Do you see some way to add flexibility yet without adding a branch point in the code?
It's impossible without branch point in code. The question is where this branch should be located.
In particular, be can put this branch point into planner by defining distinct executor nodes for each pluggable storage. In this case, each storage would have own optimized executor nodes.