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Audience
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.
Description
Want to elevate yourself to a higher level of SQL programming? Want to differentiate yourself from most SQL developers in the world today? Want to understand how to execute and understand a Db2 Explain? Want to know what it takes to get optimal performance out of queries, programs, and applications? Then this is your class! SQL statements will be broken down in detail so the participants understand in depth what the Db2 optimizer goes through in fulfilling an SQL request, and what can be done in order to get it to run faster. Time will especially be spent breaking down SQL Joins, Subqueries, and Table Expressions in order to understand the fundamental issues associated with performance. Performance-related issues in relationship to database design, indexing, efficient and effective SQL queries, and the gathering of accurate statistical information for optimization are addressed. Participants will come out of this class being ‘Empowered’ and having a much better understanding of why certain optimizations are chosen, and what can be done to change them for the better. Much of the class will be in workshops where the participants will code and review queries, execute Db2 Explains, and perform analysis on the information. Many of the workshops have the participants rewrite and/or 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.
Objectives
Upon successful completion of this course, the student will be able to:
- Display a working knowledge of the Db2 Optimizer and Access Path Selection
- Use the EXPLAIN feature of Db2
- Analyze SQL access paths
- Identify and tune poorly coded SQL Predicates
- Identify and tune poor performing Joins
- Identify and tune poor performing Subqueries
- Make appropriate SQL and access path tuning recommendations
- Identify critical catalog statistics used in access path selection
- Select appropriate statistics to gather using the RUNSTATS utility
Prerequisites
A working knowledge of Db2 for z/OS environment and the SQL language.