
xii Contents
7.1.5 Conditions and Operators 172
Comparison Conditions 172
Equi, Anti, and Range 173
LIKE Pattern Matching 173
Set Membership (IN and EXISTS) 174
Using Subqueries for Efficiency 174
Groups 175
Logical Operators 175
Set Operators 176
7.1.6 Pseudocolumns 176
Sequences 176
The ROWID Pseudocolumn 177
The ROWNUM Pseudocolumn 178
7.1.7 Joins 179
How to Code Joins in SQL Code 179
How Oracle Joins Tables 181
How to Tune a Join 183
7.2 How Oracle SQL Is Executed 184
7.2.1 The Parser 184
7.2.2 The Optimizer 185
The Importance of Statistics 186
Realistic Statistics 186
Dynamic Sampling 187
Overriding the Optimizer Using Hints 187
Classifying Hints 188
Influence ...