title: SQL: "Where" or "AND" what performs better on large database?
body: <p>I have this SQL query. It runs on the same table and creates a dataset with three columns. My concern is whether I should Use 'WHERE' clause or 'AND'. I have this feeling that 'AND' will be more efficient and faster than 'WHERE'. Please advise.
  1st one is with 'WHERE' and 2nd one is without it.</p>
  
  <ol>
  <li><p>SELECT DISTINCT t1.rpsrespondent AS id_num,t1.rpscontent AS PID, t2.RpsContent AS SeqNo<br>
  FROM table t1 
  INNER JOIN table t2 ON t1.rpsrespondent=t2.rpsrespondent 
  INNER JOIN table t3 ON t3.rpsrespondent=t1.rpsrespondent
  WHERE t1.RpsQuestion='PID' AND t2.RpsQuestion = 'VISITID' 
  AND t3.rpsquestion ='INT99' AND t3.rpscontent in('36','37')</p></li>
  <li><p>SELECT DISTINCT t1.rpsrespondent AS id_num,t1.rpscontent AS PID, t2.RpsContent AS SeqNo<br>
  FROM table t1 
  INNER JOIN table t2 ON t1.rpsrespondent=t2.rpsrespondent 
  AND t1.RpsQuestion='PID' AND t2.RpsQuestion = 'VISITID'
  INNER JOIN table t3 ON t3.rpsrespondent=t1.rpsrespondent 
  AND t3.rpsquestion ='INT99' AND t3.rpscontent in('36','37')</p></li>
  </ol>