title: Why does CHECKSUM_AGG() return same values for totally different input values?
body: <p>I don't really get how <code>CHECKSUM_AGG()</code> works, although I understood that it is somehow built by using XORs. Which explains why it returns <code>0</code> when you pass just equal integers.</p>
  
  <p>But why do I get the same aggregated checksum in the following SQL, where the input values are unique?</p>
  
  <pre><code>DECLARE @test1 TABLE (chksum INT)
  INSERT INTO @test1 VALUES (2147473855), (2147473343)
  SELECT CHECKSUM_AGG(chksum)
  FROM @test1
  
  DECLARE @test2 TABLE (chksum INT)
  INSERT INTO @test2 VALUES (2147474831), (2147472271)
  SELECT CHECKSUM_AGG(chksum)
  FROM @test2
  </code></pre>
  
  <p>An explanation would be much appreciated. Thanks!</p>