> > But needed if we want to get rid of vacuum and have savepoints.
>
> Hmm. How do you implement savepoints ? When there is rollback
> to savepoint do you use xlog to undo all changes which the particular
> transaction has done ? Hmmm it seems nice ... these resords are locked by
> such transaction so that it can safely undo them :-)
> Am I right ?
Yes, but there is no savepoints in 7.1 - hopefully in 7.2
> But how can you use xlog to get rid of vacuum ? Do you treat
> all delete log records as candidates for free space ?
Vaccum removes deleted records *and* records inserted by aborted
transactions - last ones will be removed by UNDO.
Vadim