Assumptions relating to SQL statement examples in the Database Performance and Query Optimization book

The examples of queries that are shown in this book are based on the sample tables in Appendix A, "DB2 UDB for AS/400 Sample Tables," in the SQL Programming Concepts book. For the SQL examples, assume the following:

• They are shown in the interactive SQL environment or they are written in ILE C or in COBOL. EXEC SQL and END-EXEC are used to delimit an SQL statement in a COBOL program. A description of how to use SQL statements in a COBOL program is provided in " Coding SQL Statements in COBOL Applications " of the SQL Programming with Host Languages book. A description of how to use SQL statements in an ILE C program is provided in " Coding SQL Statements in C Applications " of the SQL Programming with Host Languages book.
• Each SQL example is shown on several lines, with each clause of the statement on a separate line.
• SQL keywords are highlighted.
• Table names provided in Appendix A, "DB2 UDB for AS/400 Sample Tables" of the SQL Programming Concepts use the collection CORPDATA. Table names that are not found in Appendix A, "DB2 UDB for AS/400 Sample Tables," should use collections you create.
• Calculated columns are enclosed in parentheses, (), and brackets, [].
• The SQL naming convention is used.
• The APOST and APOSTSQL precompiler options are assumed although they are not the default options in COBOL. Character string constants within SQL and host language statements are delimited by apostrophes (').
• A sort sequence of *HEX is used, unless otherwise noted.
• The complete syntax of the SQL statement is usually not shown in any one example. For the complete description and syntax of any of the statements described in this guide, see the SQL Reference .

Whenever the examples vary from these assumptions, it is stated.

Because this guide is for the application programmer, most of the examples are shown as if they were written in an application program. However, many examples can be slightly changed and run interactively by using interactive SQL. The syntax of an SQL statement, when using interactive SQL, differs slightly from the format of the same statement when it is embedded in a program.