SQL/MX 2.x Query Guide (H06.04+, J06.03+)

Hewlett-Packard Company—540437-005
i
HP NonStop SQL/MX Query
Guide
Glossary Index Examples Figures Tables
Legal Notices
What’s New in This Manual vii
Manual Information vii
New and Changed Information viii
About This Manual xi
Audience xi
Organization xi
Related Documentation xii
Notation Conventions xv
1. Compiling and Executing a Query
Overview 1-1
How the Compiler Works 1-2
Compilation Steps 1-2
Parsing, Binding, and Normalizing 1-3
Query Plan Caching 1-5
Improving Query Performance 1-6
Factors That Can Affect Compile Time 1-19
How the Executor Processes the Plan
1-19
2. Accessing SQL/MX Data
Access Methods 2-1
Storage-Key Access 2-1
Index-Only Access 2-2
Alternate Index Access 2-4
Full Table Scan 2-5
Understanding Unexpected Access Paths 2-9
MultiDimensional Access Method (MDAM) 2-13
Specifying MDAM 2-13
Comparing MDAM With Single Subset Access 2-14
How MDAM Processes Queries 2-15