title: How to determine which version of "Oracle.DataAccess.dll" to include
body: <p>While deploying my .NET 3.5 Windows form to different environments we ran with lots of invalid provider issues.</p>
  
  <p>It works on some and doesn't work on others.</p>
  
  <p>Could someone please help me out, how do I determine which version of "Oralce.DataAccess.dll" to use i.e. 9 or 10 or 11 or 9.1.* or 10.1.* or 11.* or 12 etc.</p>
  
  <ol>
  <li><p>Does it depend on server where I'm installing an application? OR</p></li>
  <li><p>Does it depend on back end oracle database?</p></li>
  </ol>