Strategies for Data Reengineering

This paper describes and analyzes a series of strategies to migrate data-intensive applications from a legacy data management system to a modern DBMS. Considering two ways to migrate the data and three ways to propagate the corresponding perturbation to the program code, the paper identifies six reference strategies that provide different levels of quality and induce different costs. Three of them are discussed in detail and illustrated by the conversion of a legacy application based on COBOL files into an equivalent application operating on a normalized SQL database.