Optimization Techniques For Queries with Expensive Methods

ing with credit is permitted. To copy otherwise, to republish, to post on servers, to redistribute to lists, or to use any component of this work in other works, requires prior specific permission and/or a fee. Permissions may be requested from Publications Dept, ACM Inc., 1515 Broadway, New York, NY 10036 USA, fax +1 (212) 869-0481, or permissions@acm.org. 2 \Delta J.M. Hellerstein 1. OPENING One of the major themes of database research over the last 15 years has been the introduction of extensibility into Database Management Systems (DBMSs). Relational DBMSs have begun to allow simple user-defined data types and functions to be utilized in ad-hoc queries [Pirahesh 1994]. Simultaneously, Object-Oriented DBMSs have begun to offer ad-hoc query facilities, allowing declarative access to objects and methods that were previously only accessible through hand-coded, imperative applications [Cattell 1994]. More recently, Object-Relational DBMSs were developed to unify these supposedly dist..