On Tue, Aug 15, 2017 at 3:56 AM, Andres Freund <and...@anarazel.de> wrote: > I think there are some possibilities to close the gap here. We could > e.g. have <relfilenode>.delete_on_crash marker files that get installed > when creating a new persistent relfilenode. If we set up things so they > get deleted post commit, but inside the critical section, we could rely > on them being present in case of crash, but consistently removed during > WAL replay. At the end of recovery, iterate over the whole datadir and > nuke all relations with marker files present.
I agree that an approach like that has value for the problem defined in this thread. > I first thought that'd cost an additional fsync per relation > created. But I think we actually can delay that to a pre-commit phase, > if we have XLOG_SMGR_CREATE create those markers via a flag, and fsync > them just before checkpoint (via the usual delayed fsync mechanism). > That'd still require an XLogFlush(), but that seems hard to avoid unless > we just don't create relations on FS level until buffers are > evicted and/or BufferSync(). Yeah, that should work as well. -- Michael -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
