The _____ guarantees that if a portion of a transaction operation cannot be committed, all changes made at the other sites participating in the transaction will be undone to maintain a consistent database state.
A) DO-UNDO-REDO protocol
B) two-phase commit protocol (2PC)
C) coordinator protocol
D) write-ahead protocol

Question

Quizplus · Accepted Answer

The two-phase commit protocol (2PC) ensures that either all sites participating in a transaction commit or all sites abort. This ensures that the database remains in a consistent state even if a site fails to commit. The DO-UNDO-REDO protocol and write-ahead protocol are techniques used to ensure recoverability of committed transactions, but they do not address the issue of distributed transactions. The coordinator protocol is a vague term and does not refer to a specific protocol used in distributed transactions.

The _____ Guarantees That If a Portion of a Transaction