Implementation of an object oriented data model in an information system for water catchment management: Java JDO and Db4o Object Database

Object-oriented technologies are playing increasingly important roles in every level of software application for water resource management and modelling, except for data management levels where the relational logic is still the uncontested choice of information system developers despite the object–relational impedance mismatch. In this paper, we would like to present our experience concerning two different technologies for developing the object-oriented data management layer in information systems for water resources management: (i) the Java solution to obtain transparent persistence, the Java Data Object (JDO) technology; (ii) a purer object solution with a light open source Object Database, Db4o. The process for implementing the two technologies in a Java-based hydro-information system is described, and the two different solutions were analysed and compared.