TNSNAMES.ORA file

TNSNAMES.ORA is a configuration file that defines databases addresses for establishing connections to the database. It resides in ORACLE HOME\NETWORK\ADMIN directory. Below is the sample entry in TNSNAMES.ORA

<addressname> =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(Host = <hostname>)(Port = <port>))
)
(CONNECT_DATA =
(SERVICE_NAME = <sid>)
)
)