* Michael Clark: > The solution to the problem seemed to be to change the value for the > wal_sync_method setting to fsync_writethrough from the default of fsync. > I was curious if there were perhaps any other reasons that we should look > at? Or if there may be other alternatives to changing the wal_sync_method > setting. Fsync and related settings only matter if the operating system (not just the database) crashes. Does this happen frequently for you? > I should note, our product runs on OS X, and I would say about 95% of the > corruptions happen in a bytea column in a given table which tends to hold > largish data (like email bodies which may or may not have embedded > attachments). That's not surprising if 95% of the data are stored that way. > With wal_sync_method set to fsync it takes 2 seconds. > With wal_sync_method set to fsync_writethrough it takes 3 minutes and 51 > seconds. fsync_writethrough seems to be global in effect (not file specific), so it's going to hurt if there is other I/O activity on the box. -- Florian Weimer <fweimer@xxxxxx> BFK edv-consulting GmbH http://www.bfk.de/ Kriegsstraße 100 tel: +49-721-96201-1 D-76133 Karlsruhe fax: +49-721-96201-99 -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
