On Wed, Mar 18, 2015 at 2:34 AM, Kouhei Kaigai <kai...@ak.jp.nec.com> wrote: > So, overall consensus for the FDW hook location is just before the > set_chepest() > at standard_join_search() and merge_clump(), isn't it?
Yes, I think so. > Let me make a design of FDW hook to reduce code duplications for each FDW > driver, > especially, to identify baserel/joinrel to be involved in this join. Great, thanks! One issue, which I think Ashutosh alluded to upthread, is that we need to make sure it's not unreasonably difficult for foreign data wrappers to construct the FROM clause of an SQL query to be pushed down to the remote side. It should be simple when there are only inner joins involved, but when there are all outer joins it might be a bit complex. It would be very good if someone could try to write that code, based on the new hook locations, and see how it turns out, so that we can figure out how to address any issues that may crop up there. -- 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
