A.M. wrote: > > On Jan 18, 2011, at 3:55 PM, Bruce Momjian wrote: > > > I have modified test_fsync to use test labels that match wal_sync_method > > values, and and added more tests for open_sync with different sizes. > > This should make the program easier for novices to understand. Here is > > a test run for Ubuntu 11.04: > > > > $ ./test_fsync > > 2000 operations per test > > > > Compare file sync methods using one 8k write: > > (in wal_sync_method preference order, except fdatasync > > is Linux's default) > > open_datasync (non-direct I/O)* 85.127 ops/sec > > open_datasync (direct I/O) 87.119 ops/sec > > fdatasync 81.006 ops/sec > > fsync 82.621 ops/sec > > fsync_writethrough n/a > > open_sync (non-direct I/O)* 84.412 ops/sec > > open_sync (direct I/O) 91.006 ops/sec > > * This non-direct I/O mode is not used by Postgres. > > I am curious how this is targeted at novices. A naive user might enable > the "fastest" option which could be exactly wrong. For this to be useful > to novices, I suspect the tool will need to generate platform-specific > suggestions, no?
Uh, why isn't the fastest option right for them? It is hardware/kernel specific when you run it --- how could it be better? -- Bruce Momjian <br...@momjian.us> http://momjian.us EnterpriseDB http://enterprisedb.com + It's impossible for everything to be true. + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
