On Fri, Jun 3, 2016 at 11:03 PM, Robert Haas <robertmh...@gmail.com> wrote: > On Thu, Jun 2, 2016 at 11:24 AM, Masahiko Sawada <sawada.m...@gmail.com> > wrote: >> Attached patch optimises skipping pages logic so that blkno can jump to >> next_unskippable_block directly while counting the number of all_visible >> and all_frozen pages. So we can avoid double checking visibility map. > > I think this is 9.7 material. This patch has already won the > "scariest patch" tournament. Changing the logic more than necessary > at this late date seems like it just increases the scariness. I think > this is an opportunity for further optimization, not a defect. >
I agree with you. I'll submit this as a improvement for 9.7. That patch also incorporates the following review comment. We can push at least this fix. >> /* >> * Compute whether we actually scanned the whole relation. If we >> did, we >> * can adjust relfrozenxid and relminmxid. >> * >> * NB: We need to check this before truncating the relation, because >> that >> * will change ->rel_pages. >> */ >> >> Comment is out-of-date now. I'm address the review comment of 7087166 commit, and will post the patch. And testing feature for freeze map is under the discussion. Regards, -- Masahiko Sawada -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
