On Sat, Jul 24, 2021 at 02:44:13PM -0700, Andres Freund wrote:

The phoronix test uses postgres with only one relevant setting adjusted
(increasing the max connection count). That will end up using a buffer pool of
128MB, no huge pages, and importantly is configured to aim for not more than
1GB for postgres' journal, which will lead to constant checkpointing. The test
also only runs for 15 seconds, which likely isn't even enough to "warm up"
(the creation of the data set here will take longer than the run).

Given that the dataset phoronix is using is about ~16GB of data (excluding
WAL), and uses 256 concurrent clients running full tilt, using that limited
postgres settings doesn't end up measuring something particularly interesting
in my opinion.

Hi Andreas,

I tend to use the phoronix test suite for my performance runs when
testing ext4 changes simply because it's convenient.  Can you suggest
a better set configuration settings that I should perhaps use that
might give more "real world" numbers that you would find more
significant?

Thanks,

					- Ted