Cisco Technology, Inc.

Parstream Gmbh

Jörg Bienert

Norbert Heusser

Michael Hummel

Norbert Heußer

Method and apparatus for performing a database query using a bitmap index in a data-base having a plurality of bitmap vectors, the method comprising the steps of: upon receipt of a query containing a selection condition, creating a filter bitmap based on the query input; performing a bitmap scan for the filter bitmap in order to determine at least one value of an existing matching data-base entry; determining a bitmap of the determined at least one value; creating a filtered bitmap by combining the filter bitmap with the bitmap of the determined at least one value; determining all entries in the database matching the filtered bitmap; sub-tracting the filtered bitmap from the filter bitmap, thus creating a new filter bitmap; repeating the steps, starting with the step of performing a bitmap scan based on the new filter bitmap, until the step of sub-tracting results in an empty bitmap.

Method and database computer system for performing a database query using a bitmap index

System and method to compress data records by providing data records with a binary structure; dividing the data records into several bit vectors; reducing the size of each bit vector by dividing the bit vector into consecutive partial areas of equal size, each partial area consisting of n bits, classifying the partial areas as trivial partial areas, quasi-trivial partial areas and non-trivial partial areas, combining one non-trivial or several consecutive non-trivial partial areas into one so named R block, and removing the trivial partial areas; as well as combining one quasi-trivial or several consecutive quasi-trivial partial areas into one so named O block.

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Hürth, Germany

Jörg Bienert