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? FWIW, falling back to _mdfd_openseg() fixes the issue. Andres -- Sent via pgsql-hackers mailing list (firstname.lastname@example.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers