On Thu, Jan 9, 2014 at 7:42 PM, Willy-Bas Loos <willybas@xxxxxxxxx> wrote: > Hi, > > I've set up hot standby slaves for a couple of clusters. > The wal is cleaned up after use, i don't use it as a backup (yet). > It seems that the amount of wal peaks shortly after midnight, when pg_dump > is running. > > It doesn't seem logical to me that pg_dump should generate wal, but i > haven't been able to find a different explanation so far. > So to make sure, i want to ask you people: can it be that running pg_dump > creates a lot of wal? pg_dump does modify any data so it basically does not create any WAL files. But HOT pruning could, as well as data checksums in this case a plain SELECT can change some tuple hint bits, which indeed generates WAL. This reminds me of this thread: http://www.postgresql.org/message-id/E1T9G6S-0007C4-OV@xxxxxxxxxxxxxxxxxxxxxxx It would be interesting to see with xlogdump what is the WAL generated. Regards, -- Michael -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
