Re: Speed while runnning large transactions.

"Kevin Grittner" <Kevin.Grittner@wicourts.gov> writes:
> Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> As of 8.4, the typical case is that an open transaction blocks
>> deletion of rows that were deleted since the transaction's current
>> *statement* started.

[ BTW, of course that should have read "blocks removal of" ... ]

> Surely the original version of a row updated or deleted by the
> long-running transaction must be left until the long-running
> transaction completes; otherwise, how does ROLLBACK work?

Right.  What I was talking about was the impact of a long-running
transaction on the removal of rows outdated by *other* transactions.
The people who hollered loudest about this seemed to often have
long-running read-only transactions in parallel with lots of short
read-write transactions.  That's the pattern that 8.4 can help with
anyway.

            regards, tom lane