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? -- Michael -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers