External tables are files using a textual representation of records separated into fields.
The package allows for a flexible definition of the format of the file in terms of records and fields, how the information in the file should be mapped onto Prolog data types and what properties the file has to improve the performance of lookup. The table package has been used successfully to deal with large static databases such as dictionaries. Compared to loading the tables into the Prolog database, this approach required much less memory and loads much faster while providing reasonable lookup-performance on sorted tables. 1 Introduction Prolog programs sometimes need access to large sets of background data. Storage of such information as Prolog clauses is not sufficiently efficient in terms of the memory requirements.