A data structure or an integrity constraint that holds, or should hold, among the data, but that has not been explicitly declared in the DDL code of the database. Implicit compound and multivalued fields as well as implicit foreign keys are some of the most challenging constructs to chase when recovering the logical schema of a database
Published in Chapter:
Database Reverse Engineering
Jean-Luc Hainaut (University of Namur, Belgium), Jean Henrard (REVER s.a., Belgium), Didier Roland (REVER s.a., Belgium), Jean-Marc Hick (REVER s.a., Belgium), and Vincent Englebert (University of Namur, Belgium)
Copyright: © 2009
|Pages: 9
DOI: 10.4018/978-1-60566-242-8.ch021
Abstract
Database reverse engineering consists of recovering the abstract descriptions of files and databases of legacy information systems. A legacy information system can be defined as a “data-intensive application, such as [a] business system based on hundreds or thousands of data files (or tables), that significantly resists modifications and changes” (Brodie & Stonebraker, 1995). The objective of database reverse engineering is to recover the logical and conceptual descriptions, or schemas, of the permanent data of a legacy information system, that is, its database, be it implemented as a set of files or through an actual database management system.