=?UTF-8?Q?Ulf_Lohbr=C3=BCgge?= <ulf.lohbruegge@xxxxxxxxx> writes: > I'm running PostgreSQL 9.6.10 on Debian and reported some performance > issues with "SET ROLE" a while ago: > https://www.postgresql.org/message-id/CABZYQR%2BKu%2BiLFhqwY89QrrnKG9wKxckmssDG2rYKESojiohRgQ%40mail.gmail.com > ... > The setup is the same as reported in the above mentioned post: I use more > than a thousand roles per PostgreSQL instance and set the role for every > connection before executing actual statements. My pg_class consists > of 1,557,824 rows as every role has its own schema with more than 300 > tables. It seems plausible to guess that you've hit some behavior that's O(N^2) in the number of objects (for some object type or other). Perhaps "perf" or a similar tool would give some insight into where the bottleneck is. https://wiki.postgresql.org/wiki/Profiling_with_perf regards, tom lane
