Hello, Bryn. At Tue, 6 Aug 2019 15:18:51 -0700, Bryn Llewellyn <b...@yugabyte.com> wrote in <ee6d19c1-1ca6-424b-91ac-63a1a64a5...@yugabyte.com> > Here’s how I’ve tried to describe what I see for p2() with AUTOCOMMIT ON for > myself: > > 1. my call p2() starts a txn. > > 2. However, during the execution of the proc, the usual autocommit behavior > is programmatically turned off by explicit PostgreSQL code. > > 3. Other explicit PostgreSQL code makes “start transaction” inside a proc > simply cause a runtime error under all circumstances. However, txns can be > ended by “commit” or “rollback”. And new ones can be started—but only > implicitly by executing a SQL statement that, as a top level SQL, would start > a txn.
In-procedure transaction control premises that no transaction is active before calling the procedure. https://www.postgresql.org/docs/11/sql-call.html > If CALL is executed in a transaction block, then the called > procedure cannot execute transaction control > statements. Transaction control statements are only allowed if > CALL is executed in its own transaction. With AUTOCOMMIT=off, implicit BEGIN is invoked just before CALLing p2() if no transaction is active. Thus p2() is always called having a transaction active, which inhibits in-procedure transaction control. I'm not sure why you want to turn AUTOCOMNIT off, but even with AUTOCOMMIT on, explict BEGIN prevents per-command COMMIT as you perhaps know. https://www.postgresql.org/docs/11/app-psql.html > When on (the default), each SQL command is automatically > committed upon successful completion. To postpone commit in > this mode, you must enter a BEGIN or START TRANSACTION SQL > command. regards. -- Kyotaro Horiguchi NTT Open Source Software Center
