Effectively Rewriting Siebel Predefined Queries for Performance
The following is a cross-post from my co-worker Jeroen Burgers, who shares his experiences as an Oracle Implementation Advisor on his blog with the same name . In one of his recent articles, Jeroen picked up the topic of Siebel Predefined Queries (PDQ) and the impact they can have on performance. I am pleased that he agreed to publish his findings on Siebel Essentials. *** Ever had to deal with PDQs which required to fetch based on date functions such as Year-to-date or Month-to-date (or any related�)? I came across an implementation where a customer became very creative trying to resolve this. But the end-result was a terrible performance. Why? Because the PDQ could not be completely be executed as SQL. A generic implementation flaw in queries written by Siebel configurators or business analysts: misusing calculated fields to be used in e.g. search Expressions and PDQs. It can (or will) hammer performance. A lot. For example: Provide me all the Opportunities YTD. This was the original...