Rebecca Jane Rodriguez

US Patent:

50899856, Feb 18, 1992

Filed:

Apr 7, 1988

Appl. No.:

7/179181

Inventors:

Philip Y. Chang - Austin TX
Daniel J. Coyle - Austin TX
Timothy R. Malkemus - Round Rock TX
Rebecca A. Rodriguez - Pflugerville TX
Philip J. Welti - Round Rock TX

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G06F 724
G06F 1520

US Classification:

395600

Abstract:

In a relational database system, a method is utilized that increases the performance of the sort operation. An optimizer routine in the relational database manager analyzes a user's complete query to determine whether the final sorted results can be used directly by the user as sorting occurs. If the sort results can be used, the sort results are sent to Relational Data Services in the relational database manager for output to the user. Depending upon the determination made by the optimizer routine, one of two output modes for the final sorted sequence string of data are selected by the relational database manager. In disk output mode, the last pass of the final sorted sequence spring is written to disk. In fast direct output mode, the records of data are sent to the user as the final sorted sequence string is being merged during the last pass. The system and method of this invention reduces the total sort time by eliminating the overhead of writing the disk during the fast direct output mode.