Re: should there be a hard-limit on the number of transactionspending undo?

On Mon, Jul 29, 2019 at 12:39 PM Peter Geoghegan <pg@bowt.ie> wrote:
> I think that indexes (or at least B-Tree indexes) will ideally almost
> always have tuples that are the latest versions with zheap. The
> exception is tuples whose ghost bit is set, whose visibility varies
> based on the MVCC snapshot in use. But the instant that the
> deleting/updating xact commits it becomes legal to recycle the old
> heap TID.

Sorry, I meant the instant the ghost bit index tuple cannot be visible
to any possible MVCC snapshot. Which, in general, will be pretty soon
after the deleting/updating xact commits.

-- 
Peter Geoghegan