On Tue, Apr 25, 2017 at 01:37:13PM -0300, Claudio Freire wrote: > > I think it has been pretty common to accumulate a lot of such changes > > into generic entries like, say, "speedups for hash joins". More detail > > than that simply isn't useful to end users; and as a rule, our release > > notes are too long anyway. > > In that spirit, the truncation speedups it seems are missing: > > Might be summarized simply as: > > Vacuum truncation has been sped up for rotating media, sometimes > considerably (up to five times in certain configurations). > > Full commit, for reference: > > commit 7e26e02eec90370dd222f35f00042f8188488ac4 > Author: Alvaro Herrera <alvhe...@alvh.no-ip.org> > Date: Mon Jan 23 12:55:18 2017 -0300 > > Prefetch blocks during lazy vacuum's truncation scan > > Vacuum truncation scan can be sped up on rotating media by prefetching > blocks in forward direction. That makes the blocks already present in > memory by the time they are needed, while also letting OS read-ahead > kick in. > > The truncate scan has been measured to be five times faster than without > this patch (that was on a slow disk, but it shouldn't hurt on fast > disks.) > > Author: Álvaro Herrera, loosely based on a submission by Claudio Freire > Discussion: > https://postgr.es/m/cagtbqpa6nfgo_6g_y_7zqx8l9gchdsqkydo1tguh791z6py...@mail.gmail.com
I don't think this warrants inclusion in the release notes for reasons already discussed. The vacuum truncation operation is a rare one and an implementation detail. -- Bruce Momjian <br...@momjian.us> http://momjian.us EnterpriseDB http://enterprisedb.com + As you are, so once was I. As I am, so you will be. + + Ancient Roman grave inscription + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
