On Tue, Nov 15, 2016 at 7:14 AM, Tsunakawa, Takayuki <tsunakawa.ta...@jp.fujitsu.com> wrote: > From: pgsql-hackers-ow...@postgresql.org >> [mailto:pgsql-hackers-ow...@postgresql.org] On Behalf Of Amit Kapila >> Okay, not a problem. However, I am not sure the results in this thread >> are sufficient proof as for read-only tests, there is no noticeable win >> by increasing shared buffers and read-write tests seems to be quite short >> (60 seconds) to rely on it. > > I think the reason why increasing shared_buffers didn't give better > performance for read-only tests than you expect is that the relation files > are cached in the filesystem cache. The purpose of this verification is to > know that the effective upper limit is not 512MB (which is too small now), > and I think the purpose is achieved. There may be another threshold, say > 32GB or 128GB, over which the performance degrades due to PostgreSQL > implementation, but that's another topic which also applies to other OSes. >
If we don't get any benefit by increasing the shared_buffers on windows, then what advantage do you see in recommending higher value? > How about 3 minutes for read-write tests? How long do you typically run? > I generally run it for 20 to 30 mins for read-write tests. Also, to ensure consistent data, please consider changing following parameters in postgresql.conf checkpoint_timeout = 35 minutes or so, min_wal_size = 5GB or so, max_wal_size = 20GB or so and checkpoint_completion_target=0.9. Apart from above, ensure to run manual checkpoint (checkpoint command) after each test. -- With Regards, Amit Kapila. EnterpriseDB: http://www.enterprisedb.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
