View the Exhibit and examine the parameters. User A executes the following command to update the TRANS table: SQL> UPDATE B.trans SET tr_amt=tr_amt+500 WHERE c_code=’C005’;  Before user A issues a COMMIT or ROLLBACK command, user B executes the following command onthe TRANS table:  SQL> ALTER TABLE trans MODIFY (tr_type VARCHAR2(3));  What would happen in this scenario()
A:The ALTER TABLE command modifies the column successfully.
B:The DDL operation gets higher priority and transaction for user a is rolled back.
C:The ALTER TABLE command waits indefinitely until user a ends the transaction.
D:The ALTER TABLE command fails after waiting for 60 seconds due to the resource being busy.
出自:Oracle认证