Tomas, Thank you again for running all of these tests on your various hardware configurations. I was not aware of the convention that the commented example in the config file is expected to match the default value, so I was actually trying to show what to use if you didn't want the default, but I am happy to update the patch so the comment matches the default. Beyond that, I am unsure what the next steps are for this proposal.
Thanks again, Jerry On Tue, Sep 4, 2018 at 12:41 PM, Tomas Vondra <tomas.von...@2ndquadrant.com> wrote: > Hi, > > So here is the last set of benchmark results, this time from ext4 on a > small SATA-based RAID (3 x 7.2k). As before, I'm only attaching PDFs > with the simple charts, full results are available in the git repository > [1]. Overall the numbers are rather boring, with almost no difference > between the two setups. > > That being said, I'm not opposed to introducing the GUC. I'm not going > to pretend my tests represents all possible HW configs and workloads, > and I have no trouble believing that it may be quite beneficial in some > cases. > > The one comment about the code is that we usually use the actual default > value in the config sample. But the patch does this: > > +#wal_recycle = off # do not recycle WAL files > > while the GUC is defined like this: > > { > {"wal_recycle", PGC_SUSET, WAL_SETTINGS, > gettext_noop("WAL recycling enabled."), > NULL > }, > &wal_recycle, > true, > NULL, NULL, NULL > }, > > So the default is actually "on" which makes the commented-out config > sample rather confusing. > > > regards > > -- > Tomas Vondra http://www.2ndQuadrant.com > PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services >