An implementation of relational interface to an information retrieval system

摘要

In the paper a specialized relational interface to information retrieval systems is presented. Its aim is to enable the user to obtain aggregated data (e.g. total information about objects described by the database) in a simple and concise way. An additional relational database is produced by extraction of data from the main database. Data to be extracted are defined by the user in the terms of the DDL. The relational database is processed by means of the DML based on the relational algebra. Additional instructions of the DML enable the user to output relations in a tabular form and to maintain relations between subsequent executions of the manipulation program.