这个特别适合keep函数的使用场景select min(num_time)keep(dense_rank last order by abs(num)) max_num_time, min(num)keep(dense_rank last order by abs(num),num_time desc) max_num, min(num_time)keep(dense_rank first order by abs(num)) min_num_time, min(num)keep(dense_rank first order by abs(num),num_time) min_num from t;
min(num)keep(dense_rank last order by abs(num),num_time desc) max_num,
min(num_time)keep(dense_rank first order by abs(num)) min_num_time,
min(num)keep(dense_rank first order by abs(num),num_time) min_num from t;