Advanced SQL Query Building
- Recommended Duration:
- 3 Days
- Version
- DB2 Version 7. Class is suitable for those using DB2 version 5 or 6 also.
- Benefits
- The student will learn to use the EXPLAIN facility to understand physical access paths in DB2, to practice developing complex queries, and to assess the performance implications of various SQL coding techniques.
- Audience
- Experienced DB2 programmers who need to construct complex, efficient queries using SQL, or who need to tune existing complex queries for performance.
- Prerequisites
- Experience coding SQL queries, using either SPUFI or QMF.
- Major Topics
-
- Relational access concepts
- EXPLAIN and plan tables
- Access strategies
- Use of indexes
- Filter factors
- Indexable, stage 1, and stage 2 predicates
- Joined access strategies - nested loop, merge scan, hybrid
- Subqueries
- Unions
- Views and view performance
- Cursor performance
- Exercises
- There are five machine exercises.