Hotsos Symposium Speaker – Dan Tow
Mr. Tow is a prior Hotsos Symposium presenter.
Biography
Dan Tow has 18 years of experience fully focused on performance and tuning, beginning at Oracle Corporation from 1989 to 1998, followed by TenFold Corporation, from 1998 to late 2002, followed by success as an independent consultant under his SingingSQL banner. He headed the performance and tuning group for all of Oracle applications, where he cut his teeth on a rich, complex set of over 35,000 real-world applications queries. In the process, he invented a systematic, patented (USPatent #5761654) method to tune any query efficiently, which he has taught (or at least introduced) directly to over 1600 people, and this method is extended and elaborated for in a course he teaches and in his book, SQL Tuning, published by O.Reilly. He built a set of scripts to systematically, scientifically identify and prioritize performance problems, especially problems in the database and the SQL. At TenFold, as the Director of Performance and Tuning, he built much of his expertise into TenFold's application platform, EnterpriseTenFold and extended his expertise to solving database-wide and SQL-tuning problems in Sybase, DB2, and Microsoft SQLServer. He has also resolved complex performance problems in every major layer of the software, in the hardware, the operating system, and the network.
Dan lives in the United States, in Palo Alto, California, and is reachable at dantow@singingsql.com. You can view his website at www.singingsql.com, where you can also find his complete resume.
Presentation Title
Natural Data Clustering: Why Nested Loops Win so Often
Abstract
Mr. Tow will present a mix of empirical data and theoretical explanation to demonstrate why optimizers tend to favor hash joins, while experienced SQL tuners so often find they can do better by forcing nested-loops joins. The key is co-clustering - the tendency of well-clustered rows in one table to join to well-clustered rows in another table, a tendency that favors nested-loops joins.
Presentation Materials
Presentation materials are available to attendees only. Attendees may find Mr. Tow's presentation materials on Hotsos' portal. Log in using the link in the upper right corner.
Schedule
The speaker schedule can be found at the following links:
