Connection Pools on Oracle databases can be configured in two ways in OBIEE 11g.
The first way is to provide the complete connection information - which is typically found in a tnsnames.ora file - in the Data source name field of the connection pool properties.
This looks similar to the following:
Here is a sample string for your reference:
The second option is to provide only the service name (orcl in the above example). But to enable this you will have to place a valid copy of tnsnames.ora in the following directory:
and restart the BI Server.
Have a nice day