Re: An improvement of ProcessTwoPhaseBuffer logic

On Friday, December 27, 2024 10:37 MSK, Michael Paquier <michael(at)paquier(dot)xyz> wrote:

> So please see the attached. You will note that RemoveTwoPhaseFile(),
> ProcessTwoPhaseBuffer() and TwoPhaseFilePath() now require a
> FullTransactionId, hence callers need to think about the epoch to use.
> That should limit future errors compared to passing the file name as
> optional argument.

In general, I like your solution to use FullTransactionId. I haven't found any evident problems. I just would like to propose to create a couple of new functions like RemoveTwoPhaseFileInCurrentEpoch, TwoPhaseFilePathInCurrentEpoch which accept TransactionId instead FullTransactionId. It may make the code clearer and result into less boilerplate code. I tried to do some hand testing. It seems, the problem is gone with the patch. Thank you!

As an idea, I would like to propose to store FullTransactionId in global transaction state instead of TransactionId. I'm not sure, it will consume significant additional memory, but it make the code more clear and probably result into less number of locks.

With best regards,
Vitaly