> To evaluate COALESCE, e.emp_no must be known.
Why? Is it not really the case that for all practical purposes the COALESCE will always return a value How else could COALESCE(?, NULL ) [Example #3] use an index? {Nothing says that the input parameter won't be NULL} Sean ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot Firebird-Devel mailing list, web interface at https://lists.sourceforge.net/lists/listinfo/firebird-devel