Question

How do I reset a sequence in Oracle

Answer 1

 If you want to set it to 0, you can just delete and recreate it. If you want to set it to a specific value, you can set the INCREMENT to a negative value and get the next value. That is, if your sequence is at 500, you can set it to 100 via

ALTER SEQUENCE serial INCREMENT BY -400;
SELECT serial.NEXTVAL FROM dual;
ALTER SEQUENCE serial INCREMENT BY 1;