title: Testing DB Link - ORA-12154: TNS:could not resolve the connect identifier specified
body: <p>I know there is a load of times this question has been asked but I can't quite figure out how to apply this information to my situation.</p>
  
  <p>I have two databases of which I'm trying to connect with a DB LINK.  These are:</p>
  
  <ul>
  <li>BBEGMTD1</li>
  <li>OPEGMTP1.WORLD</li>
  </ul>
  
  <p>A DB link has already been defined by someone, with the name PE_DBLINK.WORLD.</p>
  
  <p>I can access <strong>both</strong> of these databases from my machine, so I can't see how tnsnames.ora would be affected.</p>
  
  <p>However when I test the DB LINK I get the famous:</p>
  
  <blockquote>
    <p>Link  : "PE_DBLINK.WORLD" Error : ORA-12154: TNS:could not resolve the
    connect identifier specified</p>
  </blockquote>
  
  <p>Could you please point me in the right direction, does the tnsnames.ora need to be modified on the BBEGMTD1 server?</p>
  
  <p>As per @Chance comment, <code>select * from ALL_DB_LINKS</code> returns:</p>
  
  <pre><code>PUBLIC                        
  PE_DBLINK.WORLD                                                                 
  PRICING                       
  OPEGMTP1.WORLD                                                                  
  03-NOV-11
  
  PUBLIC                        
  EBPROJ.WORLD                                                                    
  EBPROJ                        
  MIDGMTP1                                                                        
  17-JUN-09
  
  MYOPEGMTP1WORLD.WORLD                                                           
  PRICING                       
  (DESCRIPTION= (ADDRESS= (PROTOCOL=TCP) (HOST=ORA04SOUK) (PORT=1521) ) (CONNECT_D
  ATA= (SERVER=dedicated) (SERVICE_NAME=OPEGMTT1) ) ) )                           
  16-DEC-11
  </code></pre>
  
  <p>This is the TNSNames Editor in TOAD to show the details are being shown up:</p>
  
  <p><img src="https://i.stack.imgur.com/ErFEA.png" alt="enter image description here"></p>