Use one of the following methods to specify the database connection information for the instant client application:

• For OCI and OCCI programs, use the following connection string format:

  host[:port][/service_name][:server][/instance_name]

• Set the TNS_ADMIN environment variable to specify the location of the tnsnames.ora file and specify a service name from that file.

• Set the TNS_ADMIN and the TWO_TASK environment variables to specify a service name from the tnsnames.ora file.

  Note:

  You do not need to specify the ORACLE_HOME variable.

After checking the environment variable, you can use any of the following methods to specify Oracle Database connection information for client applications: