DB2 Forum Meeting Jan 21

Robert Brock

DB2 Forum Meeting Jan 21
DB2 Forum - The Southwest DB2 Users Group. Visit our webpage at:

Come to the 1st Quarter DB2 Forum Meeting.
DB2 Forum would like to thank Compuware Corporation for sponsoring this meeting.

Date: Tuesday January 21st, 2003

Registration & Continental Breakfast: 8:00 A.M. - 9:00 A.M

Meeting: 9:00 A.M. - 12:30 P.M.

Meeting Location:
Omni Mandalay Hotel at Las Colinas
221 East Las Colinas Blvd
Dallas, TX 75039
(972) 556-0800

Meeting Cost: $10 for non-members, free to members.
Membership is $25 per year per person --or--
$100 for 5 people in a company --or--
$350 for unlimited people in a company.
You can register at the meeting.

Chuck Hoover - Compuware Corp.

First Presentation Overview
Much has been made of the sophistication of DB2's access paths and optimizer. Looking "under the covers," DB2 actually only has two fundamental access paths and they have been available in data management since the indexed sequential access methods of the second-generation machine. All of the other "paths" use these two much like a child can assemble simple Lego blocks into complex structures.

This presentation walks through the access paths using a sample database and the IBM DB2 Estimator for Windows performance-estimating package. By associating numeric values with the many variations of the two access paths, the user of DB2 can gain a much better appreciation of what is and what is not a good access path. Special emphasis will be placed on DB2's three joining techniques and how they really work with a well-designed database.

Second Presentation Overview
Understanding the Sort for DB2 z/OS and OS/390

Sorting is a fundamental operation in information technology. SQL uses the term 'ordering' rather than sorting. This implies that optimization logic is free to select the access path with or without sorting. DB2 results sets vary from just a few rows and columns to millions of very wide rows. Sorting small result sets can be done very cheaply in central storage. This is not the case with very large result sets. For these, sorting may represent a large part of the time required to satisfy the SQL statement.

This presentation provides information about DB2 sort logic and resource utilization so System Administrators and Database Administrators can allocate the resources required for optimum sorting or, perhaps, indexes to avoid sorting. A methodology is described so an installation can gauge the efficiency of its sorts and make any necessary tuning adjustments.

Speaker Biography

Chuck Hoover is an independent consultant available for consultation on data base design, capacity planning, performance forecasting, SQL optimization and system tuning.

Chuck has over 42 years experience in information processing with the IBM Corporation and the Compuware Corporation. He has specialized on database for the last 33 years having started with the release of IBM's Information Management System/360 Version 2. His experience with the relational model extends for over 21 years and on DB2 since the early installation program for Version 1 Release 1 in 1983.