I asked the guy who did our upgrade about this earlier and this is his reply. Would this not be true?
"The danger of having the DBMS cache setting this high all the time is--data input accumulates in the DBMS cache and no data is committed to the database until the DBMS cache is filled. Only then is the data committed. Prior to the data being committed the data input can be seen in the database but until it is committed a sudden unexpected shutdown of the server would cause a rollback of the database to the state at which the last cache commit occurred. Any data waiting to be committed would be lost and would have to be reentered. This could mean days, even weeks of lost data"