How do savepoints work within a transaction?
- Allow for partial rollback
- Commit the entire transaction
- Isolate a transaction
- Terminate the transaction
Savepoints allow for partial rollback within a transaction, providing a way to undo part of the transaction without affecting the entire operation.
In SQL, the command ________ is used to permanently save changes made by the current transaction.
- BEGIN TRANSACTION
- COMMIT
- ROLLBACK
- SAVEPOINT
The COMMIT command in SQL is used to permanently save changes made by the current transaction.
The ability of a transaction to operate independently of other transactions is known as __________.
- Atomicity
- Consistency
- Durability
- Isolation
The ability of a transaction to operate independently of other transactions is known as Isolation.
A transaction's property ensuring that either all its operations are completed successfully, or none are, is known as _________.
- Atomicity
- Consistency
- Durability
- Isolation
A transaction's property ensuring that either all its operations are completed successfully, or none are, is known as Atomicity.
A transaction in a financial application requires updating multiple accounts. If one update fails, what should happen to ensure data consistency?
- Commit the successful updates
- Ignore the failed update and proceed
- Log the failure and retry the update
- Rollback the entire transaction
In a financial application, to ensure data consistency, it's crucial to rollback the entire transaction if any update within it fails. This helps maintain the integrity of the financial data.
In transaction management, what does the term 'ACID' stand for?
- Advanced Commitment Integration Design
- All Committed in Database
- Association of Commitment in Databases
- Atomicity, Consistency, Isolation, Durability
'ACID' stands for Atomicity, Consistency, Isolation, and Durability, which are the key properties ensuring reliable and secure database transactions.
How does a database ensure data integrity during concurrent transactions?
- ACID properties
- Optimistic concurrency control
- Transactions isolation levels
- Using locks
Databases ensure data integrity during concurrent transactions through transactions isolation levels, which define the visibility of changes made by one transaction to other transactions. These levels include Read Uncommitted, Read Committed, Repeatable Read, and Serializable, each providing a different balance between performance and data consistency.
What is the role of the 'rollback' statement in transaction management?
- Committing the changes made by the current transaction
- Ending the current transaction
- Initiating a new transaction
- Reversing the changes made by the current transaction
The 'rollback' statement in transaction management is used to undo the changes made by the current transaction. If an error occurs or a condition is met, the 'rollback' command ensures that all changes made so far in the transaction are rolled back, maintaining data consistency.
The isolation level that allows neither dirty reads nor non-repeatable reads is called _________.
- Read Committed
- Read Uncommitted
- Repeatable Read
- Serializable
The Serializable isolation level ensures neither dirty reads nor non-repeatable reads, providing the highest level of isolation.
The concept of ________ allows multiple users to make changes to the database without affecting each other.
- Concurrency Control
- Consistency Management
- Isolation
- Transaction Control
The concept of Concurrency Control allows multiple users to make changes to the database concurrently without affecting each other, ensuring data integrity and consistency.