On Tue, Apr 4, 2017 at 10:09 AM, Kyotaro HORIGUCHI <horiguchi.kyot...@lab.ntt.co.jp> wrote: > Hello, > > At Fri, 31 Mar 2017 18:20:23 +0900, Masahiko Sawada <sawada.m...@gmail.com> > wrote in <cad21aobn-hsih7hep8ey6nuwqgwyj0o7emuartas-6+cyaf...@mail.gmail.com> >> On Wed, Mar 29, 2017 at 12:46 PM, Kyotaro HORIGUCHI >> <horiguchi.kyot...@lab.ntt.co.jp> wrote: >> > Hello, it would be too late but I'd like to propose this because >> > this cannot be back-patched. >> > >> > >> > In autovacuum logs, "%u skipped frozen" shows the number of pages >> > skipped by ALL_FROZEN only in aggressive vacuum. >> > >> > So users cannot tell whether '0 skipped-frozen' means a >> > non-agressive vacuum or no frozen-pages in an agressive vacuum. >> > >> > I think it is nice to have an indication whether the scan was >> > "agressive" or not in log output. >> >> Good idea. I also was thinking about this. > > Thanks. Currently we cannot use "skipped-frozen" to see the > effect of ALL_FROZEN. > >> > Like this, >> > >> >> LOG: automatic aggressive vacuum of table >> >> "template1.pg_catalog.pg_statistic": index scans: 0 >> > >> > "0 skipped frozen" is uesless in non-aggressive vacuum but >> > removing it would be too-much. Inserting "aggressive" reduces >> > machine-readability so it might be better in another place. The >> > attached patch does the following. >> > >> >> LOG: automatic vacuum of table "postgres.public.pgbench_branches": >> >> mode: normal, index scans: 0 >> >> LOG: automatic vacuum of table "postgres.public.pgbench_branches": >> >> mode: aggressive, index scans: 0 >> > >> >> Should we add this even to the manual vacuum verbose message? > > I forgot that. The patch adds the mode indication in the first > message of VACUUM VERBOSE. > > | =# vacuum freeze verbose it; > | INFO: vacuuming "public.it" in aggressive mode > | INFO: "it": found 0 removable, 0 nonremovable row versions in 0 out of 0 > pages > ... > | Skipped 0 pages due to buffer pins, 0 frozen pages. > > I still feel a bit uneasy about the word "aggressive" here.
I think we can use the word "aggressive" here since we already use the word "aggressive vacuum" in docs[1], but it might be easily misunderstood. [1] https://www.postgresql.org/docs/9.6/static/routine-vacuuming.html >Is it better to be "freezing" or something? An another idea can be something like "prevent wraparound". The autovaucum process doing aggressive vacuum appears in pg_stat_activity with the word ".... (to prevent wraparound)". This word might be more user friendly IMO. Regards, -- Masahiko Sawada NIPPON TELEGRAPH AND TELEPHONE CORPORATION NTT Open Source Software Center -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
