Online Documentation for Data Comparer for Oracle

Advanced connectionon settings

You need the installed Oracle client on the client computer where Data Comparer for Oracle will be used. The version of the Oracle client should be compatible with the version of Oracle server you need to connect to.


You need to add the connection settings of Oracle server databases to your TNS names file (tnsnames.ora file), which is a configuration file that contains databases description.


If you use Database Client the tnsnames.ora file is located in the %HOME_name\NETWORK\ADMIN directory.


If you use Instant Client for Oracle, you should create tnsnames.ora file manually. File should be created in the same directory where Oracle instant client is installed (e.g. C:\OracleInstantClient\). This file can be created using any text editor: create a simple text file and then change its name and extension.


Only for Instant Client: After the tnsnames.ora file is created and database description is added, create TNS_ADMIN environment variable. For this please do the following:

  1. Right-click 'My computer'.
  2. Select 'Properties' menu item.
  3. Proceed to the 'Advanced' tab and press 'Environment Variables' button.
  4. Press 'New...' button in the 'System variables' section.
  5. Set 'Variable name:' TNS_ADMIN, 'Variable value:' C:\OracleInstantClien\tnsnames.ora
  6. Press 'OK' button to save the variable.


Find PATH variable in the same dialog, double-click it and add path to the Oracle Instant client libraries (they are located in the directory where the client is installed, i.e. C:\OracleInstantClient\). Remember that the paths entries should be separated with semicolons ( ; ).


Data Comparer for Oracle connects to the server (with the help of Oracle client) via TCP/IP protocol. Here is an example of TCP/IP connection specified in TNS names file:


DB_Alias =



(ADDRESS = (PROTOCOL = TCP)(HOST = Host_name)(PORT = 1521))




(SERVICE_NAME = Database_Name)




PROTOCOL is the keyword that identifies the specific protocol adapter used. For this protocol, the value is TCP. The value can be entered in either uppercase or lowercase.

HOST is the host name or IP address.

PORT is the TCP/IP port number.

SERVICE_NAME is the name of service on server; the database instance name may differ from the actual database name, but generally the names match.

DB_Alias is any name of the connection


At the first step select Oracle client HOME in Database home drop-down list and select database from the Database drop-down list. The databases names are taken from the tnsnames.ora file.