{ ROWS | RANGE } { 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 } }
For information on the symbols and conventions of Backus-Naur Form (BNF) syntax, see Appendix A.