Heikki Linnakangas <[EMAIL PROTECTED]> writes:
> We wouldn't clean up tuples that are visible to a transaction, but if 
> you have one long-running transaction like pg_dump in a database with 
> otherwise short transaction, you'll have a lot of tuples that are not 
> vacuumable because of the long-running process, but are not in fact 
> visible to any transaction.

It sounds to me like you are proposing to remove the middles of update
chains, which would break READ-COMMITTED updates initiated by the older
transactions.  Now admittedly pg_dump isn't going to issue any such
updates, but VACUUM doesn't know that.

                        regards, tom lane

---------------------------(end of broadcast)---------------------------
TIP 4: Have you searched our list archives?


Reply via email to