This volume is the proceedings of the Second InternationalConference on Deductive and Object-Oriented Databases(DOOD). During the last decade, deductive andobject-oriented systems have received a great deal ofattention, but for the most part these two fields wereevolving independently of each other. Today there is a largebody of work suggesting that the deductive andobject-oriented paradigms complement each other.The object-oriented paradigm is characterized by its view ofthe data, whereby information is grouped around objects withcomplex internal structure accessed via methods. Thedeclarative paradigm is centered around the idea that datamanipulation must be done through a declarative, logic-basedlanguage. It is hoped that these two aspects, broughttogether in one system, will provide an integrated frameworkfora new database technology.The DOOD conference brings together researchers anddevelopers in the fields of deductive and object-orienteddatabases to stimulate technical discussion and acceleratethe integration of the two technologies. This volumecontains 28 contributed papers (selected from 98submissions) and two invited papers by world-renownedresearchers.