On Fri, 2013-05-10 at 18:32 +0100, Simon Riggs wrote: > We don't write() WAL except with an immediate sync(), so the chances > of what you say happening are very low to impossible.
Are you sure? An XLogwrtRqst contains a write and a flush pointer, so I assume they can be different. I agree that it sounds unlikely that blocks 100 and 102 would be written, but not 101. But perhaps that's more likely in systems like ZFS where the physical blocks might be in very different places. Regards, Jeff Davis -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers