Regardless of method, first the Oracle client, at least the Instant Client, must be installed on the SQL Server box.

For a linked server connection, you'll need a TNSNAME. However, have you investigated either of these two options? This would be my first attempt, but I'm not sure if it will work.

Reply back if you find a solution and get it working. I could use it myself on occasion, but am too busy to dick around with it.

OPENROWSET

( { 'provider_name' , { 'datasource' ; 'user_id' ; 'password'

| 'provider_string' }

, { [ catalog. ] [ schema. ] object

| 'query'

}

| BULK 'data_file' ,

{ FORMATFILE = 'format_file_path' [ <bulk_options> ]

| SINGLE_BLOB | SINGLE_CLOB | SINGLE_NCLOB }

} )

https://msdn.microsoft.com/en-us/library/ms190312(v=sql.105).aspx

OPENDATASOURCE ( provider_name, init_string )

https://msdn.microsoft.com/en-us/library/ms179856(v=sql.105).aspx