The handling of user preferences is becoming an increasingly important issue in present-day information systems. Among others, preferences are used for information filtering and extraction to reduce the volume of data presented to the user. They are also used to keep track of user profiles and formulate policies to improve and automate decision making. We propose here a simple, logical framework for formulating preferences as preference formulas. The framework does not impose any restrictions on the preference relations and allows arbitrary operation and predicate signatures in preference formulas. It also makes the composition of preference relations straightforward. Preference Queries |