Thanks for the reply Jeff,
I know 20ms is nothing but it shows me that there is a problem with my
configuration. I want to find it.
I've vacuumed table but it didn't work either.
After vacuum, query start to using another index.
I run query a few times so result comes from cache with both query
=?UTF-8?Q?Ulf_Lohbr=C3=BCgge?= 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 rep