title: What's the difference between pls_integer and binary_integer?
body: <p>I've inherited some code which is going to be the base for some additional work. Looking at the stored procs, I see quite a lot of associative-arrays.</p>
  
  <p>Some of these are indexed by binary_integers, some by pls_integers. Are there any differences between the two?</p>
  
  <p>I had a look at <a href="http://docs.oracle.com/database/121/LNPLS/datatypes.htm#LNPLS319" rel="noreferrer">the documentation</a>, but apart from this line: </p>
  
  <blockquote>
    <p>The PL/SQL data types <code>PLS_INTEGER</code> and <code>BINARY_INTEGER</code> are identical. For simplicity, this document uses PLS_INTEGER to mean both <code>PLS_INTEGER</code> and <code>BINARY_INTEGER</code>.</p>
  </blockquote>
  
  <p>I couldn't find any difference between the two. So what's the difference? Are both around for historical/compatibility reasons?</p>
  
  <p>I'm using Oracle 10gR2</p>