On Fri, Oct 9, 2020 at 3:50 PM Bharath Rupireddy <bharath.rupireddyforpostg...@gmail.com> wrote: > > On Fri, Oct 9, 2020 at 3:26 PM Amit Kapila <amit.kapil...@gmail.com> wrote: > > > > On Fri, Oct 9, 2020 at 2:52 PM Bharath Rupireddy > > <bharath.rupireddyforpostg...@gmail.com> wrote: > > > > > > On Tue, Sep 29, 2020 at 6:30 PM Amit Kapila <amit.kapil...@gmail.com> > > > wrote: > > > > > > > > From the testing perspective, > > > > 1. Test by having something force_parallel_mode = regress which means > > > > that all existing Copy tests in the regression will be executed via > > > > new worker code. You can have this as a test-only patch for now and > > > > make sure all existing tests passed with this. > > > > > > > > > > I don't think all the existing copy test cases(except the new test cases > > > added in the parallel copy patch set) would run inside the parallel > > > worker if force_parallel_mode is on. This is because, the parallelism > > > will be picked up for parallel copy only if parallel option is specified > > > unlike parallelism for select queries. > > > > > > > Sure, you need to change the code such that when force_parallel_mode = > > 'regress' is specified then it always uses one worker. This is > > primarily for testing purposes and will help during the development of > > this patch as it will make all exiting Copy tests to use quite a good > > portion of the parallel infrastructure. > > > > IIUC, firstly, I will set force_parallel_mode = FORCE_PARALLEL_REGRESS > as default value in guc.c, >
No need to set this as the default value. You can change it in postgresql.conf before running tests. > and then adjust the parallelism related > code in copy.c such that it always picks 1 worker and spawns it. This > way, all the existing copy test cases would be run in parallel worker. > Please let me know if this is okay. > Yeah, this sounds fine. > If yes, I will do this and update > here. > Okay, thanks, but ensure the difference in test execution before and after your change. After your change, all the 'copy' tests should invoke the worker to perform a copy. > > > > > All the above tests are performed on the latest v6 patch set (attached > > > here in this thread) with custom postgresql.conf[1]. The results are of > > > the triplet form (exec time in sec, number of workers, gain) > > > > > > > Okay, so I am assuming the performance is the same as we have seen > > with the earlier versions of patches. > > > > Yes. Most recent run on v5 patch set [1] > Okay, good to know that. -- With Regards, Amit Kapila.
