Exam 1z0-071 topic 1 question 194 discussion

UPDATE is DML and not a DDL, it does not implicitly commit the transaction. C. The DELETE command will wait for HR’s transaction to end then delete the row. ALICE’s DELETE command will wait for HR’s transaction to complete (either commit or rollback) and then delete the row.

- When HR executes the UPDATE statement, Oracle places a row-level lock (also known as a TM lock) on the row with employee_id = 109. This lock prevents other sessions, including ALICE's, from modifying or deleting the same row until HR's transaction is either committed or rolled back. - ALICE’s DELETE command will detect the lock on the row with employee_id = 109 and wait for HR’s transaction to complete. - Once HR commits the update, the row is no longer locked. However: -Oracle’s Read Consistency Rule ensures that ALICE's session operates under the "view" of the data at the point in time when ALICE started her session (or query). -Since the row has been modified after ALICE’s session began, ALICE's DELETE will fail with an ORA-08177: Cannot serialize access for this transaction error, because the row has been changed by another committed transaction.

D is correct. Alice needs Session previlages (not just Select).

I'm seeing a lot of debate here about the security, but what about data lock? nothing indicates that the HR committed the update, thus; shouldn't the row be locked?

C gives ORA-41900

D is correct. ALICE needs SELECT privileges also

Tested, C is correct, i updated row as sys user and deleted as test user, it was stuck in scrip runner, as soon as I commited in sys session delete did happen in test user session

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