Oracle Distributed Systems

Chapter 2. SQL*Net and Net8

SQL*Net and Net8 are the network protocols Oracle supplies to support communication with an Oracle database over a network. Net8 is the new moniker for SQL*Net which Oracle has introduced with Oracle8.

Protocol Overview

Even if a process is running on the same machine as the database instance, it requires SQL*Net or Net8 to establish its database connection and to perform operations such as record fetching. SQL*Net or Net8 is required for communication between servers and clients and between servers and other servers. This software makes the entire networked database environment appear as a single machine even though multiple machines and network protocols may be involved. Before delving into the architecture and management of SQL*Net/Net8, I’ll provide an introduction to this software’s role in a distributed database environment.

Distributed Processing

Although database transactions are performed on the database server, they are usually not initiated there. A transaction may originate from a mouseclick on a web page or a bar code scan at a grocery store or a button pushed on a Touch- Tone phone—to name a few examples. SQL*Net/Net8 coordinates the communications associated with distributed transactions by establishing connections between clients and servers (or servers and servers), transmitting data back and forth, and disconnecting cleanly. SQL*Net/Net8 is also responsible for translating any differences in character sets or data representations that ...