ChangeSet
  2006/10/09 19:51:41+04:00 gkodinov@macbook.local 
  Bug #22781: SQL_BIG_RESULT fails to influence sort plan
   Currently SQL_BIG_RESULT is checked only at compile time.
   However, additional optimizations may take place after
   this check that change the sort method from 'filesort'
   to sorting via index. As a result the actual plan
   executed is not the one specified by the SQL_BIG_RESULT
   hint. Similarly, there is no such test when executing
   EXPLAIN, resulting in incorrect output.
   The patch corrects the problem by testing for
   SQL_BIG_RESULT both during the explain and execution
   phases.