From oracle 11gr2, DBMS_PARALLEL_EXECUTE package can be used for updating large tables in parallel using chunk option.

Basically, it does two steps.

1. Divides the table data into small chunks.
2. Apply DML change on each chunk parallely.

This method improves the performance the large DML operations, without consuming too much of rollback segment.

Lets check the below example.

TABLE_OWNER   -> DBACLASS
TABLE_NAME    ->  TEST100
DML STATEMENT -> Update dbaclass.test100 set OBJECT_ID=10 where NAMESPACE=1;

1. Create one task:

2. CHUNK the table by row_id:

3. Run the DML update procedure(RUN_TASK)

DML completed successfully and it took 21 seconds only.