What kind of transaction in procedure?

Question

Hello,
I have a procedure to reset sequences in tables:
CREATE OR REPLACE PROCEDURE reset_sequence AS
BEGIN
     LOCK TABLE table_name_1, table_name_2 IN EXCLUSIVE MODE NOWAIT;
     EXECUTE IMMEDIATE 'DROP SEQUENCE SEQ_1';
     EXECUTE IMMEDIATE 'CREATE SEQUENCE SEQ_1 START WITH 1 MAXVALUE 999999999999999999999999999 MINVALUE 1 NOCYCLE NOCACHE NOORDER';
     UPDATE table_name_1 SET id = SEQ_1.NEXTVAL;
     EXECUTE IMMEDIATE 'DROP SEQUENCE SEQ_2';
     EXECUTE IMMEDIATE 'CREATE SEQUENCE SEQ_2 START WITH 1 MAXVALUE 999999999999999999999999999 MINVALUE 1 NOCYCLE NOCACHE NOORDER';
     UPDATE table_name_2 SET id = SEQ_2.NEXTVAL;
     COMMIT;
END reset_sequence;
My question is: how can I do this procedure in one transaction? Set to serializable for session? This procedure have high prority, but when it's executed, other process can insert to these tables and I want to prevent it.
Thanks.

Answer 1

That's easy, just fix the column:
SQL> create table t(c number(8));
Table created.
SQL> desc t
Name                                      Null?    Type
C                                                  NUMBER(8)
SQL> alter table t modify (c number);
Table altered.
SQL> desc t
Name                                      Null?    Type
C                                                  NUMBER