International Business Machines Corporation

Stephen A Schmitt

Jerry D Dixon

William Garrett Verdoorn, Jr

Gerald U Merckel

Robert H Farrell

Peter B Bandy

Jack D Neely

A method and apparatus for performing data base searches in which the host processor and main memory are free for other processing tasks between the time that the host processor requests the search until the search results are reported back to the host processor. To commence the search, an input/output controller communicates from the host processor to a record scan circuit values of a skip length, a key length and a data length. While data records are received serially from disk files, within each data record, a length of data equal to the specified skip length is initially skipped. Following this, a search argument is compared with a length of data specified by the key length value. This comparison operation is alternated with skipping of data specified by the data length value until the end of the record is reached or until a specified number of comparisons has taken place. The data record is stored as it is received from the files. If a successful comparison is found within a data record, either the entire data record or a specified portion thereof can be read back through the controller to the host processor.

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Rochester, MN, United States of America

Stephen A Schmitt