SQL & PL/SQL :: Update Cursor - Fetch Out Of Sequence

I'm currently facing a non-critical situacion while trying to update a table. Here's the PL/SQL Code. It's a pretty straight-forward script, It just update one single column of the table. The only problem is that I have to update over 15 milions records. When I use the for update cursor, I put inside the loop a counter, when it reaches 1000 records, then commit, else keep counting.

The block throws the exception ORA-01002: fetch out of sequence.

I've tried to do some reserch on Google, buy it only says it is an out of secuence fetch caused by a commit inside a for update cursor.

My question is. Is there any risk by putting the commit under the end loop, I mean by doing this I'd be updating over 15.000.000 records at the same time. Will I have any issue with the rollback segment ?

Here's the code as along with the Create Table and Insert statements.

CREATE TABLE TEST_1
(
TEST_ID NUMBER PRIMARY KEY,
IS_LOCKED NUMBER NOT NULL
);

INSERT INTO TEST_1
(TEST_ID, IS_LOCKED)
VALUES
(1, 0);

[Code]....