Re: CheckpointStartLock starvation

Tom Lane wrote:
> Heikki Linnakangas <heikki(at)enterprisedb(dot)com> writes:
>> Tom Lane wrote:
>>> Nor will that work for prepared xacts --- you don't want to wait for the
>>> eventual commit, only for PREPARE TRANSACTION to exit its critical
>>> section.
>
>> PREPARE TRANSACTION wouldn't set the flag in MyProc; there's no clog
>> changes to protect from at that point. It would be set in
>> RecordTransactionCommitPrepared when we're really committing. Just like
>> we use the CheckpointStartLock today.
>
> Indeed --- you'd better take another look at where we use the
> CheckpointStartLock today.

Yeah, while writing the patch I noticed that we really do use it in
EndPrepare to avoid a similar race condition with the twophase state file..

--
Heikki Linnakangas
EnterpriseDB http://www.enterprisedb.com