Conventions Used in This Book

The following typographical conventions are used in this book:


Used for filenames, directory names, table names, field names, and exampl URLs. It is also used for emphasis and for the first use of a technical term.

Constant width

Used for examples and to show the contents of files and the output of commands. Also used for column names, XML element names, regular expressions, SQL literals mentioned in the text, and function names.

Constant width italic

Used in syntax descriptions to indicate user-defined items.

Constant width bold

Indicates user input in examples showing an interaction. Also indicates emphasized code elements to which you should pay particular attention.

Constant width bold italic

Used in code examples to emphasize aspects of the SQL statements, or results, that are under discussion.


In syntax descriptions, indicates keywords.


In syntax descriptions, indicates user-defined items, such as variables.

[ ]

In syntax descriptions, square brackets enclose optional items.

{ }

In syntax descriptions, curly brackets enclose a set of items from which you must choose only one.


In syntax descriptions, a vertical bar separates the items enclosed in curly or square brackets, as in {TRUE | FALSE}.

. . .

In syntax descriptions, ellipses indicate repeating elements.

Indicates a tip, suggestion, or general note. For example, we use notes to point you to useful new features in Oracle Database 10g.

Indicates a warning or caution. For example, we'll tell you if a certain SQL clause might have unintended consequences if not used carefully.