hive窗口函数报错

待理解

Error while compiling statement: FAILED: SemanticException Failed to breakup Windowing invocations into Groups.  At least 1 group must only depend on input columns.  Also check for circular dependencies.  Underlying error: Expecting right window frame boundary for function dense_rank() Window Spec=[PartitioningSpec=[partitionColumns=[(tok_table_or_col report_moth)]orderColumns=[(tok_table_or_col severity_rate) DESC NULLS_LAST]]window(type=ROWS, start=Unbounded PRECEDING, end=currentRow)] as dense_rank_window_0 to be unbounded.  Found : 2147483647