Description of the illustration windowing_clause.eps

{ ROWS | RANGE | GROUPS }
{ BETWEEN
  { UNBOUNDED PRECEDING
  | CURRENT ROW
  | value_expr { PRECEDING | FOLLOWING }
  } 
  AND
  { UNBOUNDED FOLLOWING
  | CURRENT ROW
  | value_expr { PRECEDING | FOLLOWING }
  }
| { UNBOUNDED PRECEDING
  | CURRENT ROW
  | value_expr PRECEDING
  }
}
 [ EXCLUDE CURRENT ROW
	| EXCLUDE GROUPS
	| EXCLUDE TIES
	| EXCLUDE NO OTHERS ]