On Tue, Dec 15, 2015 at 11:08 AM, Andres Freund <and...@anarazel.de> wrote: >> However, I don't think this is exactly what you are proposing. I'm >> skeptical of the idea that _mdfd_getseg() should probe ahead to see >> whether we're dealing with a malformed relation where the intermediate >> segments still exist but have zero length. > > That's not exactly what I was thinking of. I'm was thinking of doing a > _mdnblocks(reln, forknum, v) == RELSEG_SIZE check in _mdfd_getseg()'s > main loop, whenever nextsegno < targetseg. That'll make that check > rather cheap. Which sounds pretty much like your 2).
Hmm, yes it does. But now that I think about it, we're not otherwise doing _mdnblocks() in that loop. So that would add a system call per loop iteration. That doesn't seem like such a swell idea. If you're OK with it, I think I'll commit the original patch. That seems like a good thing to do regardless of what we decide about the rest of this. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (firstname.lastname@example.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers