Optimizer: SAP DB 7.3
Factors that Influence the Processing of an SQL Statement
Runtime Improvement for SQL Applications
Search Condition
Equality Condition
Area Condition
IN Condition
LIKE Condition
Search Strategy
Sequential Search
Search Conditions for Key Columns
Search Conditions for Single-Column Inverted Columns
Examples: Search Conditions for Single-Column Inverted Columns
Search Conditions for Multi-Column Inverted Columns
Examples: Search Conditions for Multi-Column Inverted Columns
Search Conditions for UPDATE Statements
Cost Determination
Search Conditions Linked with OR
Postponement of the Search to the FETCH Time
Join
List of All Search Strategies
CATALOG KEY ACCESS
CATALOG SCAN
CATALOG SCAN USING USER EQUAL CONDITION
DIFFERENT STRATEGIES FOR OR-TERMS
EQUAL CONDITION FOR INDEXED COLUMN
EQUAL CONDITION FOR INDEXED COLUMN (SUBQ)
EQUAL CONDITION FOR KEY COLUMN
EQUAL CONDITION FOR KEY COLUMN (SUBQ)
EQUAL CONDITION FOR MULTIPLE INDEX
IN CONDITION FOR INDEXED COLUMN
IN CONDITION FOR KEY COLUMN
IN CONDITION FOR MULTIPLE INDEX
INTERSECTION OF COLUMN INDEXES
JOIN VIA INDEXED COLUMN
JOIN VIA KEY COLUMN
JOIN VIA KEY RANGE
JOIN VIA MULTIPLE INDEXED COLUMNS
JOIN VIA MULTIPLE KEY COLUMNS
JOIN VIA RANGE OF MULTIPLE INDEXED COL.
JOIN VIA RANGE OF MULTIPLE KEY COLUMNS
MULTIPLE INDEX COLUMN USED (INDEX SCAN)
NO STRATEGY NOW (ONLY AT EXECUTION TIME)
RANGE CONDITION FOR INDEXED COLUMN
RANGE CONDITION FOR KEY COLUMN
RANGE CONDITION FOR KEY COLUMN (SUBQ)
RANGE CONDITION FOR MULTIPLE INDEX
RANGE CONDITION FOR MULTIPLE INDEX (SUBQ)
'ORDER BY' VIA INDEXED COLUMN
'ORDER BY' VIA MULTIPLE INDEX
SINGLE INDEX COLUMN USED (INDEX SCAN)
TABLE SCAN
EXPLAIN Statement
EXPLAIN Statement for Joins
EXPLAIN Statement for Complicated SELECT Statements
EXPLAIN Statement for SELECT Statements with Subqueries
EXPLAIN Statement: Columns O,D,T,M
Terms and Examples
Single-Column Index
Single-Column Inverted Column
Multi-Column Index
Multi-Column Inverted Column
Inversion List
Examples
example
ind
indf
invcolumn1
invcolumn2
one
ten1
ten2