Query optimisation using a data dictionary

摘要

Data dictionaries are playing an increasingly important role as repositories for information about all the data belonging to an organisation. Through the provision of sophisticated end user facilities, database management system implementors are encouraging high-level interface access to databases. However, it is often alleged that this type of database access is very costly. In this paper we describe the use of a data dictionary in the implementation of a high-level query interface to CODASYL databases. A feature of the query interface is its use of database monitoring information, stored in the data dictionary, to optimise the processing of queries.