Re: Plans for solving the VACUUM problem

> Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us> writes:
> > I am confused why we can't implement subtransactions as part of our
> > command counter? The counter is already 4 bytes long. Couldn't we
> > rollback to counter number X-10?
>
> That'd work within your own transaction, but not from outside it.
> After you commit, how will other backends know which command-counter
> values of your transaction to believe, and which not?

Seems we would have to store the command counters for the parts of the
transaction that committed, or the ones that were rolled back. Yuck.

I hate to add UNDO complexity just for subtransactions.

Hey, I have an idea. Can we do subtransactions as separate transactions
(as Tom mentioned), and put the subtransaction id's in the WAL, so they
an be safely committed/rolledback as a group?

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