I’ve attached the sample code.
Here are the key lines:
TimeSpan aTimeSpan = new TimeSpan(0, 0, 50);
TransactionSettings tSettings = new TransactionSettings(UseDTCOption.True ,
System.Transactions.IsolationLevel.ReadUncommitted, aTimeSpan);
QueryStrategy defaultStrategy = new QueryStrategy(FetchStrategy.CacheThenDataSource,
MergeStrategy.PreserveChanges, tSettings);
PersistenceManager manager = PersistenceManager.DefaultManager;
manager.DefaultQueryStrategy = defaultStrategy;