Tapio Lahdenmaki

Speaker Details


His Areas of expertise are Performance estimates (father of QUBE and VQUBE), index design (developed Three-Star Algorithm), application performance monitoring (designed Spike Report), DB2 for z/OS, IMS. From 1971-2003 he was working for International Business Machine (IBM): SE, SR, SE, Instructor, FSC SE, Instructor, ICP Solution Architect, Course developer. Author of a book on IMS database design (DL/I-tietokantojen suunnittelu, WEILIN+GOOS, 1984), co-author of two books on relational databases More than 30 articles in trade magazines, dozens of presentations outside IBM (user groups, universities etc). Currently writing a book on relational database performance with two Finnish co-authors, to be published in May 2003 (Tietokantojen suunnittelu ja indeksointi, Docendo Finland SanomaWSOY).

Since March 1 2003, independent consultant and instructor.

Past presentation
13 June 2006
09:00 - 09:45
SQLAdria Seminar – Dubrovnik 2006 Performance Tuning with Exception Monitoring

12 June 2006
16:00 - 16:45
SQLAdria Seminar – Dubrovnik 2006 Helping the DB2 for z/OS V8 Optimizer

09 June 2004
10:00 - 11:00
SQLAdria Seminar – Dubrovnik 2004 Reducing hardware costs using Buffer Pools and Index Tuning

In many companies DB2 tuning is now more about reducing costs than about improving response times. Wise trade-offs require up-to-date knowledge of hardware prices on a common scale (CPU second, 1 GB of central storage per month, 1 GB of read cache per month, 1 GB of disk space per month).
The presentation suggests a cost model, which can be tailored to your environment. It also discusses the tuning areas that have the highest potential for cost reduction. Index improvement is covered in detail with numerous examples.

07 June 2004
12:15 - 13:15
SQLAdria Seminar – Dubrovnik 2004 Reorganization and Free Space Strategies

With current disks, sequential read is much faster than random read (down to 0.1 ms per 4K). To get the benefit of this, your sequential scans should be really sequential. Leaf page splits add random reads to sequential index scans and misplaced table rows add random reads to clustered index scans with table access.

Some indexes and tables need lots of distributed free space, some do not need any. It makes sense to classify your tables and indexes according to the insert pattern. Row length plays a role as well. Both index and table rows are getting longer than they used to be. How should you specify free space if the average row length is 1,000 bytes?

The presentation recommends reorganization and free space strategies for both indexes and tables. It is based on a study by the DB2 User Group in Finland.

28 November 2003
12:30 - 13:15
SQLAdria Seminar – Opatija 2003 How To Survive 2004 – 2005

28 November 2003
10:45 - 12:15
SQLAdria Seminar – Opatija 2003 SQL Performance 2006

28 November 2003
09:00 - 10:30
SQLAdria Seminar – Opatija 2003 How To Manage Performance Problems

27 November 2003
15:45 - 17:15
SQLAdria Seminar – Opatija 2003 How To Reduce Cost per Transaction

27 November 2003
14:00 - 15:30
SQLAdria Seminar – Opatija 2003 How To Improve Response Times

27 November 2003
11:45 - 13:00
SQLAdria Seminar – Opatija 2003 How To Improve Response Times

27 November 2003
10:30 - 11:30
SQLAdria Seminar – Opatija 2003 SQL Performance

10 June 2003
10:15 - 11:00
SQLAdria Seminar – Dubrovnik 2003 How Come Joins Are Often Slow?

09 June 2003
10:30 - 11:45
SQLAdria Seminar – Dubrovnik 2003 Impact of New Disks on Database Dessign



SQL Adria is the independent, non-profit organization that gathers relational database users for Croatia and Slovenia. It was founded 1994. and in the same year it has become the regional user group.

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