Oracle Net Services Configuration for Oracle RAC Databases
Users can access an Oracle RAC database using a client and server configuration or through one or more middle tiers, with or without connection pooling.
When connecting to an Oracle Database, you can use a connect descriptor or a net service name. For Oracle RAC databases, you can also use the Single Client Access Name (SCAN) to connect to any available instance of the Oracle RAC database.
- Database Services for an Oracle RAC Database
Each database is represented by one or more services. A service is identified by a service name, such assales.example.com
. A client uses a service name to identify the database it must access. - Naming Methods and Connect Descriptors
Each net service name is associated with a connect descriptor. A connect descriptor provides the location of the database and the name of the database service. - Easy Connect Naming Method
The Easy Connect naming method eliminates the need to look up service names in thetnsnames.ora
file or other repository for TCP/IP environments. - Understanding SCANs
The SCAN is a domain name registered to at least one and up to three IP addresses, either in domain name service (DNS) or in Grid Naming Service (GNS). - About Connecting to an Oracle RAC Database Using SCANs
Oracle recommends that you configure Oracle RAC database clients to use the SCAN to connect to the database instead of configuring thetnsnames.ora
file. - About Listener Configuration for an Oracle RAC Database
An Oracle Database receives connection requests through the local listener. - About Service Registration for an Oracle RAC Database
An Oracle Database 19c database service automatically registers with the listeners specified in the database initialization parametersLOCAL_LISTENER
andREMOTE_LISTENER
. - How Database Connections are Created When Using SCANs
Based on the environment, the following actions occur when you use a SCAN to connect to an Oracle RAC database using a service name.
See Also:
Oracle Database Net Services Administrator's Guide for more information about Oracle Net Services concepts
Parent topic: Understanding the Oracle RAC Installed Configuration