On Fri, Feb 2, 2024 at 10:02 AM Tom Lane <t...@sss.pgh.pa.us> wrote:
> Alexander Korotkov <aekorot...@gmail.com> writes: > > I'm going to push this if there are no objections. > > One of the test cases added by this commit has not been very > stable in the buildfarm. Latest example is here: > > > https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=prion&dt=2024-02-01%2021%3A28%3A04 > > and I've seen similar failures intermittently on other machines. > > I'd suggest building this test atop a table that is more stable > than pg_class. You're just waving a red flag in front of a bull > if you expect stable statistics from that during a regression run. > Nor do I see any particular reason for pg_class to be especially > suited to the test. Yeah, it's not a good practice to use pg_class in this place. While looking through the test cases added by this commit, I noticed some other minor issues that are not great. Such as * The table 'btg' is inserted with 10000 tuples, which seems a bit expensive for a test. I don't think we need such a big table to test what we want. * I don't see why we need to manipulate GUC max_parallel_workers and max_parallel_workers_per_gather. * I think we'd better write the tests with the keywords being all upper or all lower. A mixed use of upper and lower is not great. Such as in explain (COSTS OFF) SELECT x,y FROM btg GROUP BY x,y,z,w; * Some comments for the test queries are not easy to read. * For this statement CREATE INDEX idx_y_x_z ON btg(y,x,w); I think the index name would cause confusion. It creates an index on columns y, x and w, but the name indicates an index on y, x and z. I'd like to write a draft patch for the fixes. Thanks Richard
