Thank you for your notification. At Tue, 5 Sep 2017 12:05:01 +0200, Daniel Gustafsson <dan...@yesql.se> wrote in <b3ec34fc-a48e-41aa-8598-bfc5d87cb...@yesql.se> > > On 13 Apr 2017, at 11:42, Kyotaro HORIGUCHI > > <horiguchi.kyot...@lab.ntt.co.jp> wrote: > > > > At Thu, 13 Apr 2017 13:52:40 +0900, Michael Paquier > > <michael.paqu...@gmail.com> wrote in > > <CAB7nPqTRyica1d-zU+YckveFC876=sc847etmk7trgas2pa...@mail.gmail.com> > >> On Tue, Apr 11, 2017 at 5:38 PM, Kyotaro HORIGUCHI > >> <horiguchi.kyot...@lab.ntt.co.jp> wrote: > >>> Sorry, what I have just sent was broken. > >> > >> You can use PROVE_TESTS when running make check to select a subset of > >> tests you want to run. I use that all the time when working on patches > >> dedicated to certain code paths. > > > > Thank you for the information. Removing unwanted test scripts > > from t/ directories was annoyance. This makes me happy. > > > >>>> - Relation has new members no_pending_sync and pending_sync that > >>>> works as instant cache of an entry in pendingSync hash. > >>>> - Commit-time synchronizing is restored as Michael's patch. > >>>> - If relfilenode is replaced, pending_sync for the old node is > >>>> removed. Anyway this is ignored on abort and meaningless on > >>>> commit. > >>>> - TAP test is renamed to 012 since some new files have been added. > >>>> > >>>> Accessing pending sync hash occurred on every calling of > >>>> HeapNeedsWAL() (per insertion/update/freeze of a tuple) if any of > >>>> accessing relations has pending sync. Almost of them are > >>>> eliminated as the result. > >> > >> Did you actually test this patch? One of the logs added makes the > >> tests a long time to run: > > > > Maybe this patch requires make clean since it extends the > > structure RelationData. (Perhaps I saw the same trouble.) > > > >> 2017-04-13 12:11:27.065 JST [85441] t/102_vacuumdb_stages.pl > >> STATEMENT: ANALYZE; > >> 2017-04-13 12:12:25.766 JST [85492] LOG: BufferNeedsWAL: pendingSyncs > >> = 0x0, no_pending_sync = 0 > >> > >> - lsn = XLogInsert(RM_SMGR_ID, > >> - XLOG_SMGR_TRUNCATE | XLR_SPECIAL_REL_UPDATE); > >> + rel->no_pending_sync= false; > >> + rel->pending_sync = pending; > >> + } > >> > >> It seems to me that those flags and the pending_sync data should be > >> kept in the context of backend process and not be part of the Relation > >> data... > > > > I understand that the context of "backend process" means > > storage.c local. I don't mind the context on which the data is, > > but I found only there that can get rid of frequent hash > > searching. For pending deletions, just appending to a list is > > enough and costs almost nothing, on the other hand pendig syncs > > are required to be referenced, sometimes very frequently. > > > >> +void > >> +RecordPendingSync(Relation rel) > >> I don't think that I agree that this should be part of relcache.c. The > >> syncs are tracked should be tracked out of the relation context. > > > > Yeah.. It's in storage.c in the latest patch. (Sorry for the > > duplicate name). I think it is a kind of bond between smgr and > > relation. > > > >> Seeing how invasive this change is, I would also advocate for this > >> patch as only being a HEAD-only change, not many people are > >> complaining about this optimization of TRUNCATE missing when wal_level > >> = minimal, and this needs a very careful review. > > > > Agreed. > > > >> Should I code something? Or Horiguchi-san, would you take care of it? > >> The previous crash I saw has been taken care of, but it's been really > >> some time since I looked at this patch... > > > > My point is hash-search on every tuple insertion should be evaded > > even if it happens rearely. Once it was a bit apart from your > > original patch, but in the latest patch the significant part > > (pending-sync hash) is revived from the original one. > > This patch has followed along since CF 2016-03, do we think we can reach a > conclusion in this CF? It was marked as "Waiting on Author”, based on > developments since in this thread, I’ve changed it back to “Needs Review” > again.
I manged to reload its context into my head. It doesn't apply on the current master and needs some amendment. I'm going to work on this. regards, -- Kyotaro Horiguchi 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
