On Mon, May 2, 2016 at 12:41 PM, Andres Freund <and...@anarazel.de> wrote: > On 2016-05-02 12:29:45 -0400, Robert Haas wrote: >> On Fri, Apr 29, 2016 at 7:58 PM, Andres Freund <and...@anarazel.de> wrote: >> > Basically the reason for the problem is that mdsync() needs to access >> > "formally non-existant segments" (as in ones where previous segments are >> > < RELSEG_SIZE), because we queue (and the might be preexistant) fsync >> > requests via register_dirty_segment() in mdtruncate(). >> >> Shouldn't we just throw those flush requests away? > > Well, we explicity make them for truncations (register_dirty_segment() > calls in mdtruncate()). There's no comment as to why - I suspect the > idea is that you want to make sure the truncation sticks in case of > crash?
I dunno, I don't understand this well enough yet. > FWIW, falling back to _mdfd_openseg() fixes the issue. Can you post a patch? -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
