Multilevel information system— Towards more flexible information retrieval systems

摘要

The Multilevel Information System (MLIS), extension of typical Information Retrieval System towards more complete data processing, is discussed. MLIS integrates functions typical for data base management systems and retrieval-oriented systems. Several levels of data accessing are provided, each level developed for a different class of users. End-user level is based on simple query language, trained user level on a relational model, and application programmer level on a Data Manipulation Language nested in high level programming language. The last two levels are discussed in detail.