Oracle Networks - Concepts Oracle Networks, also known as Oracle Net or SQL*Net, are a set of protocols and tools used for communication between Oracle database instances and clients. These networks play a crucial role in establishing connections, transmitting data, and managing database access. Here are some key concepts related to Oracle Networks: Listener: The Oracle Listener is a process that runs on the database server and listens for incoming connection requests. It acts as a mediator between clients and the database instance. When a client wants to connect to a database, it contacts the Listener, which redirects the connection to the appropriate database service. Service Name: A service name is a unique identifier for a particular database service within an Oracle database instance. It allows clients to connect to a specific service within a database. Service names are defined in the database's listener.ora and tnsnames.ora files. TNS (Transparent Network Substrate) Names: TNS names are a naming method used by Oracle to identify the network location and service names for database connections. These names are typically stored in a tnsnames.ora file, which acts as a local repository for resolving service names to network addresses. Connect Descriptor: A connect descriptor is a string containing network information that specifies the location of a database service. It includes details such as the database's hostname or IP address, port number, and service name. Connect descriptors are used by clients to connect to the database. SQL*Net and Oracle Net: SQLNet is the older name for Oracle Net, a set of protocols and software tools that enable communication between clients and Oracle database servers. Oracle Net encompasses protocols like TCP/IP, SQLNet, and others. It allows clients to connect to the database using a variety of methods. Protocol Support: Oracle Net supports various network protocols, including TCP/IP, HTTP, named pipes, and others. These protocols facilitate communication between clients and Oracle database instances. The choice of protocol depends on the network configuration and requirements. Listener.ora and tnsnames.ora Files: The listener.ora file is used to configure the Listener, specifying the services it should listen for and the protocol it should use. The tnsnames.ora file contains network service definitions, such as service names and connect descriptors, allowing clients to connect to database services. Database Services: In Oracle, a database service is a logical representation of a database, and it can include one or more database instances. Each database service has a unique name and can be configured for various purposes, such as load balancing and high availability. Advanced Networking Features: Oracle Net offers advanced features such as connection pooling, load balancing, failover, and encryption for secure communication. These features help improve performance, scalability, and security in Oracle database environments. Oracle Net Configuration Tools: Oracle provides various tools and utilities for configuring Oracle Net, including the Oracle Net Configuration Assistant (NetCA) and the Oracle Net Manager. These tools simplify the setup and management of network configurations. Next Topic » (Oracle Networks - Listeners)