How ro/rw routing works?

[troelsarvin]

I'm trying to understand how load balancing works, specifically the automatic routing of read-only requests to the standby database server:
If a session starts with a clean SELECT but then starts doing UPDATEs also: Will PgDog then re-connect to the primary DB for the update? If so: I suppose it cannot do that, unless the session is in a "low consistency" isolation level, i.e. not in repeatable read mode? If so: How does it work, does PgDog look out for SET TRANSACTION statements?

[g4lb]

PgDog routes each statement, not the session. A BEGIN transaction goes to the primary as a whole (docs).