Hi! On Wed, Jul 25, 2018 at 1:19 PM Simon Riggs <si...@2ndquadrant.com> wrote: > On 13 July 2018 at 03:14, Imai, Yoshikazu <imai.yoshik...@jp.fujitsu.com> > wrote: > > From an attached graph("some_contention_points_on_leaf_nodes.png"), as > > contention points dispersed, we can see that TPS is increased and TPS > > difference between master and patched version becomes smaller. > > So I think this clearly shows the drop in throughput when we have > index contention and that this patch improves on that situation. > > In cases where we don't have contention, the patch doesn't cause a > negative effect. > > So +1 from me!
Thank you, but Imai found another case [1], where patch causes a small regression. For now, it's not completely clear for me what test case was used, because I forgot to add any indexes to initial specification of this test case [2]. If regression will be confirmed, then it would be nice to mitigate that. And even if we wouldn't manage to mitigate that and consider that as acceptable trade-off, then it would be nice to at least explain it... 1. https://www.postgresql.org/message-id/0F97FA9ABBDBE54F91744A9B37151A51189451%40g01jpexmbkw24 2. https://www.postgresql.org/message-id/CAPpHfds%3DWmjv%2Bu7S0peHN2zRrw4C%3DYySn-ZKddp4E7q8KQ18hQ%40mail.gmail.com------ Alexander Korotkov Postgres Professional: http://www.postgrespro.com The Russian Postgres Company