Fred --
Yes, the slave database(s) can be safely used in a R/O mode, given the issue you raise of not necessarily having an up-to-date copy of the data in the master. We haven't ever run enough queries against a slave to reveal any lurking contention issues, if indeed there are any, relating to the inserts/updates being done by the dbmirror perl code (such a momentary locks), so this may need some testing under stress.
HTH,
Greg Williamson
DBA
GlobeXplorer LLC
Hi,
Does anybody know if the slave database(s) in the dbmirror replication model can be queried (via SQL SELECT statement) by a client program as if it is quering the master database (I understand that the slave database may not be a 100% mirror of the master at any given moment but that is good enough) ? We are exploring the possibility of a multi-server architecture where the master postgres database would handle all the data update maintenance workload whereas the slave(s) would handle all the query workload.
Any suggestions would be much appreciated.
TIA.
Fred
