Re: PG and undo logging

Ravi Krishna <sravikrishna3(at)gmail(dot)com> writes:
> Thanks for the detailed explanation. The explanation makes me wonder
> that PG must do more work at commit time, right?

No. Commit and abort are both O(1). Where we pay the piper is in
having to run VACUUM to clean up no-longer-needed row versions.

This is a better design in principle, because the necessary maintenance
can be done in background processes rather than making clients wait
for transactions to finish. In practice, it's still pretty annoying,
just in different ways than Oracle's UNDO.

regards, tom lane