So, a natural question arises like why do we need to push the changes to database from middle-tier and without committing?
Imagine a scenarios where you have a PL/SQL procedure which you need to run after some rows has been inserted/modified in your application. Before you issue a commit everything will remain in the middle-tier. A PL/SQL procedure will run on the database and hence in such scenario your PL/SQL procedure will not be able to get the latest changes which are available in the middle-tier.
So, here comes the postChanges method which you can use to push the middle-tier changes to the database without actually committing.