1976	 Multi-attribute Retrieval with Combined Indexes	 In this paper a file organization scheme designed to replace the use of the popular secondary index filing scheme or inverted files on secondary key fields is described. Through the use of redundancy and storing keys or access numbers of the records that satisfy different combinations of secondary index values in buckets it is possible to retrieve all keys satisfying any input query derived from a subset of fields by a single access to an index file although each bucket may be used for many combinations of values and a combination of buckets may be required for a given query. The method which in its degenerate case becomes the conventional secondary index filing scheme works similarly but has the following advantages the elimination of multiple accesses in many cases the elimination of false drops the elimination of computer time to perform intersection of key sets each qualified for one secondary index field only and the avoidance of long strings of keys when an index field appearing in a query has very few possible values. Redundancy in some cases is the same as the secondary indexing method. In the general case trade-off between the number of accesses for query and redundancy exists. file organization secondary index files inverted files information retrieval data management access method secondary keys storage with buckets rapid retrieval balanced filing scheme elimination of false drops combining indexes query multi-attribute retrieval
