1 Introduction

Prolog programs sometimes need access to large sets of background data. For example in the GRASP project we need access to ontologies of art objects, a large lexicon and translation dictionaries. Storage of such information as Prolog clauses is not sufficiently efficient in terms of the memory requirements.

The table package outlined in this document allows for easy access of large structured files. The package uses binary search if possible and linear search for queries that cannot use more efficient algorithms without building additional index tables. Caching is achieved using the file-to-memory maps supported by many modern operating systems.

The following sections define the interface predicates for the package. Section 4 provides an example to access the Unix password file.