On Tue, Jun 6, 2017 at 12:16 PM, Mengxing Liu <liu-m...@mails.tsinghua.edu.cn> wrote: > I think disk I/O is not the bottleneck in our experiment, but the global lock > is.
A handy way to figure this kind of thing out is to run a query like this repeatedly during the benchmark: SELECT wait_event_type, wait_event FROM pg_stat_activity; I often do this by using psql's \watch command, often \watch 0.5 to run it every half-second. I save all the results collected during the benchmark using 'script' and then analyze them to see which wait events are most frequent. If your theory is right, you ought to see that SerializableXactHashLock occurs as a wait event very frequently. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (email@example.com) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers