>
> Well, flushing the meta-data of pg_twophase is really going to be far
> cheaper than the many pages done until CheckpointTwoPhase is reached.
> There should really be a check on serialized_xacts for the
> non-recovery code path, but considering how cheap that's going to be
> compared to the rest of the restart point stuff it is not worth the
> complexity of adding a counter, for example in shared memory with
> XLogCtl (the counter gets reinitialized at each checkpoint,
> incremented when replaying a 2PC prepare, decremented with a 2PC
> commit). So to reduce the backpatch impact I would just do the fsync
> if (serialized_xact > 0 || RecoveryInProgress()) and call it a day.
Sounds ok to me. I will leave it to the committer to decide further.
--
Best Wishes,
Ashutosh Bapat
EnterpriseDB Corporation
The Postgres Database Company