postgres 8.2.3 transaction xid wraparound

["Sriram Dandapani" <sdandapani(at)counterpane(dot)com>]

I have been using postgres 8.1 for a while now with large databases (over 300-400G). The biggest issue I have faced is the routine vacuumdb command that takes care of the transaction id wraparound problem (I run this once a week on each postgres box and it takes about 24-48 hours depending on the load and size of databse).   (autovacuum just doesn’t work for me as I need to routinely shut down postgres briefly and restart)

 

I run the following command to determine when to kick of vacuuming..

 

Select datname,age(datfrozenxid) from pg_database

 

 

With 8.2.3….what is the query I need to run to check age of xid for wraparound purposes (I read from the docs that it is now maintained on a per-table basis..does this mean if I were to vacuum tables individually..i would not need to run a vacuumdb on the database cluster?)

 

Thanks

 

Sriram