From: "Bruce Momjian" <pgman@candle.pha.pa.us>
> And finally, I must abort tuple changes made by the aborted
> subtransaction. One way of doing that is to keep all relation id's
> modified by the transaction, and do a sequential scan of the tables on
> abort, changing the transaction id's to a fixed aborted transaction id.
> However, this could be slow. (We could store tids if only a few rows
> are updated by a subtransaction. That would speed it up considerably.)
Are you sure you don't want to use the log for this? It does mean that the
log can grow without bound for long-lived transactions, but it's very
straightforward and fast.
Ken Hirsch