On 7 May 2014 08:17, Kouhei Kaigai <kaigai@ak.jp.nec.com> wrote:
> Let me clarify. This mechanism allows to add alternative scan/join paths
> including built-in ones, not only custom enhanced plan/exec node, isn't it?
> Probably, it is a variation of above proposition if we install a handler
> function that proposes built-in path nodes towards the request for scan/join.
Yes, I am looking for a way to give you the full extent of your
requirements, within the Postgres framework. I have time and funding
to assist you in achieving this in a general way that all may make use
of.
> Not only alternative data structure, alternative method to scan/join towards
> same data structure is also important, isn't it?
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.
-- Simon Riggs http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training & Services