On Wed, Sep 20, 2017 at 12:47 AM, Tom Lane <t...@sss.pgh.pa.us> wrote: > Amit Kapila <amit.kapil...@gmail.com> writes: >> On Tue, Sep 19, 2017 at 9:27 AM, Michael Paquier >> <michael.paqu...@gmail.com> wrote: >>> I am not saying that no index AMs take advantage FPW compressibility >>> for their meta pages. There are cases like this one, as well as one >>> code path in BRIN where this is useful, and it is useful as well when >>> logging FPWs of the init forks for unlogged relations. > >> Hmm, why is it useful for logging FPWs of the init forks for unlogged >> relations? We don't use REGBUF_STANDARD in those cases. > > But if we started to do so, that would be a concrete benefit of this > patch ...
In the proposed set of patches, all the empty() routines part of index AMs which use log_newpage_buffer() (brin, gin, spgst) are doing the right thing by updating log_newpage_buffer(). btree also should have its call to log_newpage updated in btbuildempty(), and your patch is missing that. Also, _hash_init() would need some extra work to generate FPWs, but I don't think that it is necessary per its handling of a per-record meta data either. So REGBUF_STANDARD could be just removed from there, and there is actually no need to patch src/backend/access/hash at all. -- Michael -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
