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.