If an SQL exception occurs in a method that performs multiple database updates, how should the exception be handled to maintain data integrity?
- Commit all changes made before the exception
- Ignore the exception and continue with the remaining updates
- Log the exception and terminate the transaction
- Rollback all changes made before the exception
When an SQL exception occurs during multiple updates, rolling back all changes made before the exception helps maintain data integrity by ensuring either all updates succeed or none do.
When designing an application that connects to a database, how should SQL exceptions be managed to provide meaningful feedback to the user?
- Display the raw SQL exception message
- Log the exception and display a user-friendly error message
- Show a generic error message to the user
- Terminate the application on exception
To provide meaningful feedback, log the SQL exception for debugging purposes and display a user-friendly error message to the user, avoiding the display of raw SQL exception messages that may expose sensitive information.
The translation of JSP to servlet occurs in the ______ phase.
- Compiling
- Execution
- Initialization
- Parsing
The translation of JSP to servlet occurs in the compiling phase. JSP pages are translated to servlets before they are compiled into bytecode and executed on the server.
In JDBC, what does Statement.setFetchSize(int rows) method influence?
- Database table indexing
- Number of rows fetched at a time
- Query execution timeout
- Transaction isolation level
The setFetchSize(int rows) method in JDBC influences the number of rows fetched at a time from the result set, which can impact the performance and memory usage of the application.
How does the use of 'lazy loading' in an ORM framework like Hibernate affect database performance?
- Decreases performance by loading all data at once
- Depends on the specific use case
- Has no impact on performance
- Increases performance by loading data on demand
'Lazy loading' in Hibernate increases performance by loading data on demand, reducing the initial load time and resource consumption.
What are the implications of using optimistic vs. pessimistic locking strategies in database transactions?
- Both have similar implications
- Optimistic locking prevents blocking, may lead to conflicts
- Pessimistic locking reduces contention, but can cause blocking
- They are used interchangeably based on convenience
Optimistic locking in database transactions prevents blocking but may lead to conflicts, while pessimistic locking reduces contention but can cause blocking due to exclusive locks.
Explain the role of database indexing in query optimization.
- Depends on the size of the database and data distribution
- Has no impact on query optimization
- Slows down queries by adding complexity
- Speeds up data retrieval by providing faster access
Database indexing plays a crucial role in query optimization by speeding up data retrieval. Indexes provide faster access to specific data, reducing the time it takes to execute queries, especially in scenarios with large datasets.
Reducing the number of database ________ can significantly improve performance in a web application.
- connections
- indexes
- queries
- transactions
Reducing the number of repeated SQL queries can significantly improve performance in a web application.
_________ is a technique used to minimize the cost of repeatedly executing similar SQL queries.
- Caching
- Normalization
- Sharding
- Triggers
Caching is a technique used to minimize the cost of repeatedly executing similar SQL queries by storing the results of expensive operations and returning the cached result when the same operations occur.
In a scenario where a transaction involves multiple SQL queries, how should exceptions be handled to ensure that either all queries succeed or none do?
- Commit each query individually
- Commit the entire transaction only if all queries succeed
- Ignore exceptions and continue with the transaction
- Rollback the entire transaction on any exception
Handling exceptions in a transaction involving multiple SQL queries requires rolling back the entire transaction on any exception to ensure data consistency鈥攅ither all queries succeed, or none do.