SQL/MX 2.x Query Guide (G06.24+, H06.03+)

Contents
HP NonStop SQL/MX Query Guide—523728-003
iii
5. Forcing Execution Plans (continued)
5. Forcing Execution Plans (continued)
Translating the Operator Tree to Text Format 5-5
Using SHOWSHAPE and SET SHOWSHAPE to View the Text Format 5-5
Using Visual Query Planner to Get the Shape 5-6
Manually Writing the Shape 5-7
Writing the Forced Shape Statement 5-8
Scope of CONTROL QUERY SHAPE 5-8
Shaping Portions of an Operator Tree 5-9
Using Logical and Physical Specifications 5-9
Forcing Shapes on Views 5-10
What Happens if No Plan Is Returned? 5-10
Migrating Forced Shapes From SQL/MP 5-10
Forcing Group By Operations to the Data Access Manager 5-10
Forcing Parallel Plans 5-13
6. Query Plan Caching
Overview 6-1
Types of Cacheable Queries 6-2
Examples of Cacheable Expressions 6-3
Examples of Queries That Are Not Cacheable 6-4
Choosing an Appropriate Size for the Query Cache 6-6
Query Plan Caching Statistics 6-6
SYSTEM_DEFAULTS Table Settings for Query Plan Caching Attributes 6-7
QUERYCACHE Function 6-9
QUERYCACHEENTRIES Function 6-11
Querying the Query Plan Caching Virtual Tables 6-13
Reviewing the Query Plan Caching Statistics With the DISPLAY_QC and
DISPLAY_QC_ENTRIES Commands 6-15
7. Operators and Operator Groups
Operator Groups and Operators 7-2
CALL Operator 7-4
CURSOR_DELETE Operator 7-5
CURSOR_UPDATE Operator 7-6
ESP_EXCHANGE Operator 7-6
EXPLAIN Operator 7-8
EXPR Operator 7-8
FILE_SCAN Operator 7-8
FILE_SCAN_UNIQUE Operator 7-10