Oracle7 Server Concepts

**SQL*Net**

SQL*Net is the Oracle network interface that allows Oracle tools running on network workstations and servers to access, modify, share, and store data on other servers. SQL*Net is considered part of the program interface in network communications. See Chapter 9, "Memory Structures and Processes",.for more information about the program interface.

SQL*Net uses the communication protocols or application programmatic interfaces (APIs) supported by a wide range of networks to provide a distributed database and distributed processing for Oracle. A communications protocol is a set of standards, implemented in software, that govern the transmission of data across a network. An API is a set of subroutines that provide, in the case of networks, a means to establish remote process-to-process communication via a communication protocol.

Communication protocols define the way that data is transmitted and received on a network. In a networked environment, an Oracle server communicates with client workstations and other Oracle servers using SQL*Net. SQL*Net supports communications on all major network protocols, ranging from those supported by PC LANs to those used by the largest mainframe computer systems.

Without the use of SQL*Net, an application developer must manually code all communications in an application that operates in a networked distributed processing environment. If the network hardware, topology, or protocol changes, the application has to be modified accordingly.

However, by using SQL*Net, the application developer does not have to be concerned with supporting network communications in a database application. If the underlying protocol changes, the database administrator makes some minor changes, while the application requires no modifications and will continue to function.

**How SQL*Net Works**

SQL*Net drivers provide an interface between Oracle processes running on the database server and the user processes of Oracle tools running on other computers of the network.

The SQL*Net drivers take SQL statements from the interface of the Oracle tools and package them for transmission to Oracle via one of the supported industry-standard higher level protocols or programmatic interfaces. The drivers also take replies from Oracle and package them for transmission to the tools via the same higher level communications mechanism. This is all done independently of the network operating system.

Additional Information: Depending on the operating system that executes Oracle, the SQL*Net software of the database server may include the driver software and start an additional Oracle background process; see your Oracle operating system-specific documentation for details.

For additional information on SQL*Net, refer to Understanding SQL*Net or the appropriate SQL*Net documentation.