On Mon, Jun 26, 2017 at 10:54 AM, Michael Paquier <michael.paqu...@gmail.com> wrote: > On Fri, Jun 23, 2017 at 11:17 AM, Amit Langote > <langote_amit...@lab.ntt.co.jp> wrote: >> That was it, thanks for the pointer. > > GinInitMetabuffer() sets up pd_lower and pd_upper anyway using > PageInit so the check of PageIsVerified is guaranteed to work in any > case. Upgraded pages will still have their pd_lower set to the > previous values, and new pages will have the optimization. So this > patch is actually harmless for past pages, while newer ones are seen > as more compressible. > >> Attached updated patch, which I confirmed, passes wal_consistency_check = >> gin. > > I have spent some time looking at this patch, playing with pg_upgrade > to check the state of the page upgraded. And this looks good to me. > One thing that I noticed is that this optimization could as well > happen for spgist meta pages. What do others think?
Good point. I think it could happen for brin meta page as well. Regards, -- Masahiko Sawada NIPPON TELEGRAPH AND TELEPHONE CORPORATION NTT Open Source Software Center -- Sent via pgsql-hackers mailing list (email@example.com) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers