The Evils of Implicit Conversions and other SQL Skullduggery

Presented by Tom Kyte

Thurs 21st June 2012

This webinar has now finished, but feel free to click the button above to watch the recording.

Summary

SQL and PL/SQL are deceptively simple, user-friendly languages, which is great for productivity, but also makes it relatively easy to write bad, non-scalable code. Certain features, in particular, seem to sound an irresistible siren call into a world of Oracle applications that perform poorly and yield unpredictable results.

In this webinar, Tom Kyte, a Senior Technical Architect at Oracle Corporation, and the man behind asktom.oracle.com, takes a look at a few of the worst offenders:

• Triggers - much trickery is possible via triggers, and much of it causes pain, confusion and unexpected side effects
• Indexes, NULLs and cardinality - misinformation abounds with regard to the effect of NULLs on cardinality estimates, and the impact of NULLs on index use
• Implicit conversions - strings to numbers, strings to dates, raw to string... probably #2 on the list of 'bugs I see time and time (and time) again'

With Tom's typically example-driven approach, you'll see first-hand evidence of the damage caused when fundamental features are misused, misunderstood and implemented badly.

A live Q+A session with Tom follows the presentation.

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Tom Kyte

Tom Kyte is a Senior Technical Architect in Oracle's Server Technology Division. Tom is the Tom behind the AskTom column in Oracle Magazine, answering people's questions about the Oracle database and its tools. He is also the author of Expert Oracle Database Architecture (Apress, 2005/2009), Expert One on One Oracle(Wrox Press, 2001/Apress 2004), Beginning Oracle Programing (Wrox press, 2002/Apress 2004), and Effective Oracle by Design (Oracle Press, 2003). These are books about the general use of the database and how to develop successful Oracle applications.

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