How should a developer handle a scenario where a stored procedure returns multiple result sets?
- Close the connection and reopen it
- Ignore additional result sets
- Use multiple ResultSets and process each separately
- Use only the first result set
To handle multiple result sets returned by a stored procedure, the developer should use multiple ResultSets and process each one separately. Ignoring additional result sets or closing and reopening the connection are not appropriate solutions.
In a transactional context, if one of the PreparedStatement executions fails, what should be the approach for handling this situation?
- Commit the successful executions, ignore the failure
- Continue with the next PreparedStatement
- Manually undo the changes of successful executions
- Rollback the entire transaction
In a transactional context, if one of the PreparedStatement executions fails, the appropriate approach is to rollback the entire transaction to maintain data consistency. Committing successful executions and ignoring the failure may lead to inconsistent data.
What is the primary purpose of transaction management in database operations?
- Encrypting data
- Ensuring data consistency
- Managing user permissions
- Optimizing queries
The primary purpose of transaction management is to ensure data consistency by either committing or rolling back changes as a single, atomic operation.
Which SQL statement is used to start a transaction in a database?
- BEGIN TRANSACTION
- COMMIT TRANSACTION
- ROLLBACK TRANSACTION
- START TRANSACTION
The START TRANSACTION statement is used to begin a transaction in a database, marking the starting point for a series of SQL statements to be treated as a single unit.
In what scenarios is CallableStatement preferable over PreparedStatement?
- Executing SQL queries with input parameters
- Handling batch updates
- Handling stored procedure calls
- Optimizing read-only operations
CallableStatement is preferable when dealing with stored procedures as it allows the execution of precompiled SQL queries, making it suitable for scenarios where stored procedures are used.
What is the difference between 'dirty read' and 'non-repeatable read' in the context of transaction isolation levels?
- Dirty read: Reading committed data
- Dirty read: Reading uncommitted data
- Non-repeatable read: Reading committed data
- Non-repeatable read: Reading uncommitted data
In the context of transaction isolation levels, a 'dirty read' occurs when a transaction reads uncommitted data from another transaction, while a 'non-repeatable read' happens when a transaction reads data committed by another transaction but the data changes before the first transaction completes. Understanding these concepts is crucial in managing data consistency and isolation in concurrent transactions.
How do distributed transactions differ from local transactions?
- Concurrency and Durability
- Consistency and Recovery
- Isolation and Atomicity
- Scope and Participants
Distributed transactions involve multiple participants and a wider scope, whereas local transactions are limited to a single resource or database.
What is two-phase commit protocol in the context of transaction management?
- A protocol for authentication
- A protocol for coordination
- A protocol for data retrieval
- A protocol for voting
The two-phase commit protocol is a coordination protocol involving a voting phase and a decision phase to ensure distributed transaction consistency.
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.