From: pgsql-hackers-ow...@postgresql.org > [mailto:pgsql-hackers-ow...@postgresql.org] On Behalf Of Amit Kapila > > 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?
No, I'm not recommending a higher value, but just removing the doubtful sentences of 512MB upper limit. The advantage is that eliminating this sentence will make a chance for users to try best setting. > 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. Thank you, I'll try the read-write test with these settings on the weekend, when my PC is available. I understood that your intention is to avoid being affected by checkpointing and WAL segment creation. Regards Takayuki Tsunakawa -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
