Re: Freezing without write I/O

On Thu, May 30, 2013 at 10:04:23PM -0400, Robert Haas wrote:
> > Hm. Why? If freezing gets notably cheaper I don't really see much need
> > for keeping that much clog around? If we still run into anti-wraparound
> > areas, there has to be some major operational problem.
>
> That is true, but we have a decent number of customers who do in fact
> have such problems. I think that's only going to get more common. As
> hardware gets faster and PostgreSQL improves, people are going to
> process more and more transactions in shorter and shorter periods of
> time. Heikki's benchmark results for the XLOG scaling patch show
> rates of >80,000 tps. Even at a more modest 10,000 tps, with default
> settings, you'll do anti-wraparound vacuums of the entire cluster
> about every 8 hours. That's not fun.

Are you assuming these are all write transactions, hence consuming xids?

--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com

+ It's impossible for everything to be true. +