On Thu, Feb 4, 2016 at 3:28 PM, Etsuro Fujita <fujita.ets...@lab.ntt.co.jp> wrote:
> On 2016/02/04 17:58, Etsuro Fujita wrote: > >> On 2016/02/04 8:00, Robert Haas wrote: >> >>> On Wed, Feb 3, 2016 at 5:56 PM, Robert Haas <robertmh...@gmail.com> >>> wrote: >>> >>>> On Wed, Feb 3, 2016 at 12:08 PM, Ashutosh Bapat >>>> <ashutosh.ba...@enterprisedb.com> wrote: >>>> >>>>> PFA patches with naming conventions similar to previous ones. >>>>> pg_fdw_core_v7.patch: core changes >>>>> pg_fdw_join_v7.patch: postgres_fdw changes for join pushdown >>>>> pg_join_pd_v7.patch: combined patch for ease of testing. >>>>> >>>> > One more: I think the following in postgresGetForeignJoinPaths() is a good > idea, but I think it's okay to just check whether root->rowMarks is > non-NIL, because that since we have rowmarks for all base relations except > the target, if we have root->parse->commandType==CMD_DELETE (or > root->parse->commandType==CMD_UPDATE), then there would be at least one > non-target base relation in the joinrel, which would have a rowmark. > > Sorry, I am unable to understand it fully. But what you are suggesting that if there are root->rowMarks, then we are sure that there is at least one base relation apart from the target, which needs locking rows. Even if we don't have one, still changes in a row of target relation after it was scanned, can result in firing EPQ check, which would need the local plan to be executed, thus even if root->rowMarks is NIL, EPQ check can fire and we will need alternate local plan. -- Best Wishes, Ashutosh Bapat EnterpriseDB Corporation The Postgres Database Company
