A Survey of Current Methods for Integrity Constraint Maintenance and View Updating Enric Mayol, Ernest Teniente Universitat Politècnica de Catalunya E-08034 Barcelona - Catalonia e-mail: [mayol | teniente]@lsi.upc.es Abstract During the process of updating a database, two interrelated problems could arise. On one hand, when an update is applied to the database, integrity constraints could become violated, thus falsifying database consistency. In this case, the integrity constraint maintenance approach tries to obtain additional updates to be applied to re-establish database consistency. On the other hand, when an update request consist on updating some derived predicate, a view updating mechanism must be applied to translate the update request into correct updates on the underlying base facts. In this paper, we propose a general framework to compare and classify current methods in the field of view updating and integrity constraint maintenance. In this sense, we classify them considering how they tackle with both problems and, we also state the main drawbacks these methods have. 1. Introduction Most databases, like relational or deductive ones, allow the definition of intentional information like views or integrity constraints. Intentional information is defined by means of rules that allow to deduce new data (i.e. intentional data) from that one explicitly stored in the database (i.e. extensional data, like tuples in a relational database or base facts in a deductive one). Therefore, databases must include a query and an update processing system able to deal with this kind of information. This paper addresses some of the problems encountered during update processing and summarizes previous research in this area. Views and integrity constraints are the most traditional types of intentional information. Views are defined by means of deductive rules that allow to define new facts (view or derived facts) from stored (base) facts, while integrity constraints state conditions to be satisfied by each state of the database. Databases are updated through the application of given transactions that consist of a set of updates of base facts. When applying a transaction, database consistency may be falsified, i.e. some integrity constraint may be violated. Therefore, databases must incorporate some mechanism to ensure that integrity constraints are always satisfied after the application of a transaction. This problem is usually known as integrity constraint enforcement. There are several approaches of resolving this conflict [Win90]. All of them are reasonable and the correct approach to be considered depends on the semantics of the integrity constraints and of the database. The best known approaches are integrity constraint checking and integrity constraint maintenance.