Conventions Used in This Book

The following conventions are used in this book:

Italic

Used for file and directory names, for URLs, and for emphasis when introducing a new term.

Constant width

Used for code examples.

Constant width bold

Indicates user input in examples showing an interaction. Also, in some code examples, highlights the statements being discussed.

Constant width italic

In some code examples, indicates an element (e.g., a filename) that you supply.

UPPERCASE

In code examples, generally indicates PL/SQL keywords.

lowercase

In code examples, generally indicates user-defined items such as variables, parameters, etc.

punctuation

In code examples, enter exactly as shown.

indentation

In code examples, helps to show structure but is not required.

- -

In code examples, a double hyphen begins a single-line comment that extends to the end of a line.

/* and */

In code examples, these characters delimit a multiline comment that can extend from one line to another.

.

In code examples and related discussions, a dot qualifies a reference by separating an object name from a component name. For example, dot notation is used to select fields in a record and to specify declarations within a package.

[ ]

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 brackets, as in {TRUE | FALSE}.

...

In syntax descriptions, ellipses indicate repeating elements. An ellipsis also shows that statements or clauses irrelevant to the discussion were left out.

Indicates a tip, suggestion, or general note. For example, we'll tell you if a certain setting is version-specific.

Indicates a warning or caution. For example, we'll tell you if a certain setting has some kind of negative impact on the system.

Which Platform or Version?

In general, all of the discussions and examples in this book apply regardless of the machine and/or operating system you are using. In those cases where a feature is in any way version-dependent—for example, if you can use it only in Oracle versions Oracle8i or Oracle9i—we note that in the text.

There are many versions of PL/SQL, and you may even find that you need to use multiple versions in your development work. Chapter 1 describes the versions of PL/SQL still in common use and what you should know about them; see Section 1.4.3.