On Fri, Oct 9, 2020 at 2:34 PM Amit Kapila <amit.kapil...@gmail.com> wrote: > > On Fri, Oct 9, 2020 at 2:19 PM Simon Riggs <si...@2ndquadrant.com> wrote: > > > > On Fri, 9 Oct 2020 at 04:10, Amit Kapila <amit.kapil...@gmail.com> wrote: > > > > > > On Thu, Oct 8, 2020 at 2:34 PM Simon Riggs <si...@2ndquadrant.com> wrote: > > > > > > > > On Thu, 8 Oct 2020 at 09:47, Dilip Kumar <dilipbal...@gmail.com> wrote: > > > > > > > > > > This script will wait 10 seconds after INSERT exits > > > > > > before executing TRUNCATE, please wait for it to run. > > > > > > > > Has this been tested with anything other than the one test case? > > > > > > > > It would be good to know how the patch handles a transaction that > > > > contains many aborted subtransactions that contain invals. > > > > > > > > > > Are you thinking from the angle of performance or functionality? I > > > don't see how this patch can impact either of those. Basically, it > > > will not execute any extra invalidations then it is executing without > > > the patch for aborted subtransactions. Can you please explain in a bit > > > more detail about your fear? > > > > > > Having said that, I think it would be a good idea to test the scenario > > > you mentioned to ensure that we have not broken anything unknowingly. > > > > The test appears to only cover the case of many subtransactions, all > > of which commit, and then top-level commit occurs. > > > > We should be testing cases where the top-level commit occurs, yet some > > proportion of the subtransactions abort. "Normal" would be 10-50% > > aborts. > > > > I presume we support this case already, but wish to ensure the > > performance tweak is not just for the one special case. > > > > Okay, I think this makes sense. I think we should see the performance > benefit for this case as well but maybe to a bit lesser degree because > we will exclude some of the subtransactions from processing.
I have tried with a combination of abort/commit subtransaction and I could see a similar benefit with the patch. I tested below transaction BEGIN; truncate table nsp_001.tbl_001; savepoint s1; truncate table nsp_001.tbl_001; savepoint s2; truncate table part_0001; savepoint s3; truncate table part_0002; savepoint s5; truncate table part_0003; rollback to s3; commit; EOF -- Regards, Dilip Kumar EnterpriseDB: http://www.enterprisedb.com
