This class is designed to break down SQL statements in detail so the participants understand in depth what the Db2 optimizer goes through in fulfilling an SQL request. Time will especially be spent breaking down SQL Joins and Subqueries in order to understand the fundamental issues associated with performance. The class will address performance-related issues in relationship to database design, indexing, efficient and effective SQL queries, and the gathering of accurate statistical information for optimization. Participants will come out of this class having a much better understanding of why certain optimizations are chosen, and what can be done to get Db2 to choose differently. Much of the class will be in workshops where the participants will review queries, execute Db2 Explains, and perform analysis on the information. Many of the workshops have the participants apply tuning statements to existing queries in order to get them to perform more efficiently. Participants will know exactly what steps to take in getting poor performing SQL queries to execute more efficiently.
A working knowledge of Db2 for z/OS environment and the SQL language.
4 Days/Lecture & Lab
All personnel involved in SQL Access path performance tuning that require an in-depth understanding of the full complement of Explain Tables provided by Db2.
- Predicate Types and Performance
- Basic Access Paths and Performance
- Tuning Joins
- Aggregate Functions, SQL Subqueries & Performance
- Tables expressions and Performance
- Db2 Catalog Statistics and Access Path Selection
- Advanced Query Tuning