Oracle Net Services: The Successor to SQL*Net

Oracle Net Services, formerly known as Oracle Net, is the successor to SQLNet in Oracle database environments. Oracle Net Services is a comprehensive suite of network components that provide a robust, scalable, and secure framework for establishing and maintaining connections between Oracle database clients and servers. As the communication foundation of the Oracle database environment, Oracle Net Services replaced SQLNet to offer enhanced functionality and improved performance.
SQL*Net was the original networking protocol used in Oracle database environments to facilitate communication between clients and servers. It was designed to provide transparent and reliable connections, regardless of the underlying network protocol. However, with the advancement of technology and the increasing complexity of database environments, the need for a more sophisticated and versatile solution emerged.
Oracle Net Services was introduced to address these evolving requirements and offer a more robust and extensible communication framework. The key features of Oracle Net Services include:

1. Transparent Network Connectivity: Oracle Net Services supports various network protocols and operating systems, allowing seamless communication between Oracle clients and servers in heterogeneous environments.
2. Connection Pooling and Load Balancing: Oracle Net Services provides connection pooling and load balancing capabilities, improving scalability and performance in large-scale database environments.
3. Security: Oracle Net Services supports advanced security features, such as data encryption, integrity checking, and authentication mechanisms, ensuring secure communication between clients and servers.
4. Manageability: Oracle Net Services offers a set of tools and utilities to monitor, diagnose, and troubleshoot network-related issues in Oracle database environments.
5. Extensibility: Oracle Net Services supports a variety of pluggable network components, allowing developers to customize the communication stack to meet specific requirements.

Oracle Net Services is the successor to SQL*Net in Oracle database environments, providing a comprehensive and flexible networking solution that meets the demands of modern database systems. With its advanced features and capabilities, Oracle Net Services has become an essential component in establishing and maintaining connections between Oracle clients and servers.

SQL*Net version 1 was the first attempt by Oracle at database connectivity. In SQL*Net version 1, database connections require the request to supply all the connection information. This includes the protocol, the host name (or IP address), and the database name.
To connect to a specific database on a server using TCP/IP, you set a UNIX environment variable called TWO_TASK.
When the request is made, SQL*Net version 1 interrogates the contents of TWO_TASK to get the database information. An example of how you would make a connection from a server named fred to a server named dilbert, and then connect to a database named tom using TCP/IP:

One of the biggest shortcomings of SQL*Net version 1 was the requirement to "know" all the connection information instead of having a look-up file to get this information. In SQL*Net version 2, we see this information.
nce an incoming connection is intercepted by an Oracle listener, the request is either forwarded to a dedicated dispatcher or the listener will spawn a server-side process to host the incoming connection.
In the next lesson, the features of SQL*Net version 2 will be discussed.