On Tue, 2021-07-13 at 20:14 -0700, David G. Johnston wrote: > On Tue, Jul 13, 2021 at 8:01 PM Lucas <root@xxxxxxx> wrote: > > According to the documentation, max_standby_streaming_delay is a configuration parameter > > determining how long a standby server should wait before canceling queries that conflict > > with pending WAL entries received via streaming replication. > > > > My question then is: Which queries, if the slave can only receive SELECTs? > > The select queries... > > Follow the link in the docs for max_stanbdy_steaming_delay to: > > https://www.postgresql.org/docs/current/hot-standby.html#HOT-STANDBY-CONFLICT > > for the details. Perhaps you might find the following article interesting, where I tried to discuss this topic in some depth: https://www.cybertec-postgresql.com/en/streaming-replication-conflicts-in-postgresql/ Yours, Laurenz Albe -- Cybertec | https://www.cybertec-postgresql.com