On Fri, 2 Oct 2009, Tom Lane wrote:
> 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.
Which makes sense if you think about it. Long-running read-only reports
are quite common in DBA land. I'm sure most people can think of an
example in businesses they work with that you can't refactor away into
smaller chunks, everybody seems to have their own variation on the big
overnight report. Long-running read-write transactions are much less
common, and a bit more likely to break into logical chunks if you
architect the design right, using techniques like staging areas for bulk
operations and write barriers for when they can be applied.
--
* Greg Smith gsmith@gregsmith.com http://www.gregsmith.com Baltimore, MD