This lesson invites you to work through a simulation that gives you hands-on experience using the Oracle Net Assistant to configure the client log-on procedure.

A Program Global Area (PGA) is a memory area used by a single Oracle Database server process. When you connect to an Oracle database instance, you create a session that uses a server process for communication between the client and database instance. Each server process has its own PGA. The PGA is used to process SQL statements and to hold logon and other session information. A large part of the PGA is dedicated to SQL work areas, which are working memory areas for sorts and other SQL operations. The amount of PGA memory used and the contents of the PGA depend on whether the instance is running in dedicated server or shared server mode. The total memory used by all individual PGAs is known as the total instance PGA memory, and the collection of individual PGAs is referred to as the total instance PGA, or just instance PGA. With Database Control, you set the size of the instance PGA, not individual PGAs.

Oracle Net is backwards compatible with SQL*Net version 2. Oracle Net clients can transparently connect to an Oracle7 database. Existing SQL*Net version 2 clients can also connect to an Oracle8 database. Upgrading to Oracle Net is not required, but migrating to Oracle Net offers important advantages.

1. Oracle Net simplifies the process of setting up your network components. You can use the Oracle Oracle Net Assistant to create or modify your existing local naming files, profile, and Oracle Names configuration file.
2. Oracle Net offers extended network functionality. Many of the features previously available with SQL*Net version 2 were replaced with enhanced functionality.
3. Oracle Net includes an application program interface (API) called Oracle Net OPEN. Application developers can use Oracle Net to develop applications (database and non-database) that make use of the Oracle Net network services. One important advantage that Oracle Net OPEN offers application developers is a single common interface to all industry standard network protocols.