On Sat, 2006-10-21 at 09:00 -0400, Theo Schlossnagle wrote: > On Oct 21, 2006, at 6:08 AM, Martijn van Oosterhout wrote: > > > On Sat, Oct 21, 2006 at 10:37:51AM +0100, Simon Riggs wrote: > >> Turning off WAL is a difficult topic. Without it you have no crash > >> recovery, which IMHO everybody says they don't care about until they > >> crash, then they realise. It's hard to be selective about writing WAL > >> for specific operations also. > > > > It's been discussed before. One idea is to declare tables without > > logging. The idea being that during recovery those tables and related > > indexes are simply truncated. No foreign keys allowed. Obviously they > > will not be saved via PITR either. > > > > Put another way, the table structure is saved in WAL, but the data > > isn't. > > This is exactly what I'd like. Simon suggested turning off WAL > during the loads as a possible hack solution. The reason this won't > work is that we snap all the time, lots of tables. We have between > 2000 and 4000 snapshot operations per day (throughout). At the same > time we have reporting queries running (that create and/or populate > other tables) that last from 5 minutes to 18 hours. It is important > that we run everything but the snapshots with WAL on (as we must have > PITR -- sans snapshots)
These tables are loaded once then read-only, yes? -- Simon Riggs EnterpriseDB http://www.enterprisedb.com ---------------------------(end of broadcast)--------------------------- TIP 6: explain analyze is your friend
