On Wed, Dec 3, 2014 at 11:47 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
Atri Sharma <atri.jiit@gmail.com> writes: > On Wed, Dec 3, 2014 at 11:38 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote: >> I think the right approach for now is to emulate the GEQO precedent as >> closely as possible. Build all the single-relation Paths the same as >> now, then do a join search over all the relations, then (if we've noticed >> that some joins are potentially removable) do another join search over >> just the nonremovable relations.
> How about using geqo more liberally when replanning (decrease the number of > relations in join before geqo is hit?)
This is going to be quite difficult enough without overcomplicating it. Or as a wise man once said, "premature optimization is the root of all evil". Get it working in the basic way and then see if improvement is necessary at all.
Sure, I can take a crack at it since I am working on a patch that does require this alternative path approach. Let me try something and report my experimental results.