Final answer:
For recovery purposes, it's crucial to monitor when a transaction starts, updates data, and commits or aborts to ensure system consistency and maintain the ACID properties essential for database transactions.
Step-by-step explanation:
For recovery purposes, the system needs to keep track of when the transaction starts, updates data, and commits or aborts. This ensures that in case of a system failure, the transaction can be rolled back to a consistent state, or if it was completed, the changes can be reaffirmed. Keep tracking these stages is critical for maintaining the ACID properties (Atomicity, Consistency, Isolation, Durability) which are essential for transaction processing in databases. When a transaction starts, it signifies the beginning of a sequence of operations that constitute an atomic unit of work. Throughout the transaction, any updates to the data are recorded, which could include additions, deletions, or modifications of records. The point at which the transaction commits is where all the changes are permanently applied to the database, or if any issues arise or the transaction is deemed invalid, it aborts, wherein all changes made during the transaction are rolled back.
Begin: The transaction begins, indicating the initiation of a series of operations that should be treated as a single unit.
Execute Operations: During this phase, the transaction performs various operations on the database, such as reading or updating records.
Commit or Abort: The transaction reaches a point where it decides to either commit (make the changes permanent) or abort (rollback changes and undo the transaction).