I'm hoping someone can help me figure out how to better tune my WAL parameters. Right now I am seeing WAL activity that is faster than I think it should be - we average about 30 write queries a second at our peak, and yet we're getting a new WAL file every 15-20 seconds. Our postgresql.conf parameters: wal_level = hot_standby # minimal, archive, or hot_standby checkpoint_segments = 10 # in logfile segments, min 1, 16MB each checkpoint_timeout = 5min # range 30s-1h checkpoint_completion_target = 0.9 # checkpoint target duration, 0.0 - 1.0 #checkpoint_warning = 30s # 0 disables Here is "select * from pg_stat_bgwriter;" checkpoints_timed: 2081; checkpoints_req: 18889; buffers_checkpoint: 4320036; buffers_clean: 416180117; maxwritten_clean: 1580518; buffers_backend: 77676446; bueffers_backend_fsync: 0; buffers_alloc: 4804432940; stats_reset: "2012-06-24 23:13:10.716096-04" >From my previous research, I *think* that that data implies: 1) Due to high ratio of checkpoints_req to checkpoints_timed, I should increase checkpoints_segments, maybe from 10 to 15? 2) There are only about 206 buffers (buffers_checkpoint/(checkpoints_timed+checkpoints_req)) for each checkpoint. I think that is far lower than it should be, but I'm not positive about that, and I don't know what would increase it? 3) maxwitten_clean should be much lower than that? Thanks for your help! -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general