title: Is "LIMIT 1" recommended  for query where WHERE condition is based on PK?
body: <p>I am querying a mySQL database to retrieve the data from 1 particular row.  I'm using the table primary key as the WHERE constraint parameter.</p>
  
  <p>E.g.</p>
  
  <pre><code>SELECT name FROM users WHERE userid = 4
  </code></pre>
  
  <p>The userid column is the primary key of the table.  Is it good practice to use LIMIT 1 on the end of that mySQL statement?  Or are there any speed benefits?</p>