Today we continue our discussion on DB powder. Using DBPowder and ObjectView, developers can come up with a number of persistent classes along with each part of the application logic. In this case, a table might be used by more than one persistent class. There are many to many correspondences among persistent classes and tables and the persistent classes hold the values. Now if there are persistent objects in the same session, and they hold the same attribute value, in the same tuple, they cannot recognize each other that the attribute value is the same.  To solve this issue, DBPowder leverages ActiveRecord. The data wrapper classes and the data classes access tables using ActiveRecords. Because values of data wrappers are held in ActiveRecords and each of the data wrapper is the wrapper class of the Active Records,values in data wrapper can have a single correspondence with those in the tables. As a result, each persistent class can recognize each other that the attribute value is the same.
We now look at a Prototype system of DBPowder and a production use. The first version of the prototype system for DBPowder was implemented in JavaSE in  2006. In this paper, EER model and ObjectView support were added. The prototype included a description language, DBPowder-mdl and has a parser and code generator to interpret DBPowder-mdl and generate source code.  The prototype also generates simple web pages for create, retrieve, update and delete operations. DBPowder-mdl, the parser and the GEN were refined in this paper.
The set of web applications and the DBPowder system was applied in production for the security administration task and refined. The same set of applications were deployed to another site where the number of users in two sites were 130.