Testing an Oracle DB connection before it is made - ERROR? I tried to make a new oracle DB connection with user name and password. I entered the connection name, user name and password in the new connection window. When I click the "test" button or the "connect" button, I get the following error: 
Status : Failure - Test Failed: ORA-01017: invalid username/password; logon denied

Why am I getting this error ? What does the Test &amp; Connect button actually do ?
The error is telling your user login username or password is incorrect. Remember that from 11g onwards, passwords are case sensitive. 

The test &amp; connect button tests if the entered details (TNSName, port etc) are correct &amp; then proceeds to connect to the database. In your case, your credentials are wrong &amp; you're getting the error message.