title: Semantics of .WRITE(NULL, NULL, NULL) when updating a VARBINARY(max) column
body: <p>What are the semantics of the following query</p>
  
  <pre><code>UPDATE table
  SET column .WRITE(NULL, NULL, NULL)
  </code></pre>
  
  <p>if <code>column</code> is of <code>VARBINARY(max)</code> type and its contents are not <code>NULL</code>?</p>
  
  <p>A quick test suggests that the query
  is a no-op:</p>
  
  <pre><code>--DROP TABLE [table]
  CREATE TABLE [table] ([column] VARBINARY(max))
  INSERT INTO [table] VALUES (0x12345678)
  UPDATE [table]
  SET [column] .WRITE(NULL, NULL, NULL)
  SELECT * FROM [table]
  </code></pre>
  
  <p>Executing it does not alter the data in the <code>column</code>. However, I can't seem to find evidence in the <a href="http://msdn.microsoft.com/en-us/library/ms177523%28v=sql.105%29.aspx" rel="nofollow">documentation</a>. Have I overlooked something, or is this no-op behavior likely to change?</p>