On Thu, 2007-01-04 at 11:09 -0500, Tom Lane wrote: > "Simon Riggs" <[EMAIL PROTECTED]> writes: > > On Thu, 2007-01-04 at 10:00 -0500, Tom Lane wrote: > >> "Simon Riggs" <[EMAIL PROTECTED]> writes: > >>> Recovery can occur with/without same setting of wal_checksum, to avoid > >>> complications from crashes immediately after turning GUC on. > >> > >> Surely not. Otherwise even the "on" setting is not really a defense. > > > Only when the CRC is exactly zero, which happens very very rarely. > > "It works most of the time" doesn't exactly satisfy me. What's the > use-case for changing the variable on the fly anyway? Seems a better > solution is just to lock down the setting at postmaster start.
That would prevent us from using the secondary checkpoint location, in the case of a crash effecting the primary checkpoint when it is a shutdown checkpoint where we changed the setting of wal_checksum. It seemed safer to allow a very rare error through to the next level of error checking rather than to close the door so tight that recovery would not be possible in a very rare case. If your're good with server start, so am I. -- Simon Riggs EnterpriseDB http://www.enterprisedb.com ---------------------------(end of broadcast)--------------------------- TIP 5: don't forget to increase your free space map settings
