CYCLE or NOCYCLE Option
Use the CYCLE option to continue generating sequence values after the sequence reaches the maximum (ascending) or minimum (descending) limit, to replace the NOCYCLE attribute. After an ascending sequence reaches max, it generates the min value for the next value. After a descending sequence reaches min, it generates the max value for the next sequence value.
Use the NOCYCLE option to prevent the sequence from generating more values after reaching the declared limit. Once the sequence reaches the limit, the next reference to sequence.NEXTVAL returns an error message.