Scenario: A DBA needs to perform a point-in-time recovery in DB2 due to data corruption. What steps should they take to accomplish this?

  • Apply the last full database backup and transaction logs to recover the database to its state before corruption.
  • Perform a full database backup, restore it to a different location, and apply transaction logs up to the desired point in time.
  • Perform a table-level restore from a previous backup and replay logs to reach the desired point in time.
  • Roll back the database to the last consistent state, restart the database, and reapply transactions from the application logs.
Point-in-time recovery in DB2 typically involves restoring the database to a consistent state prior to the corruption incident. This requires performing a full database backup, restoring it to a different location, and applying transaction logs up to the desired point in time to achieve consistency. 

How does DB2 handle SQL injection attacks?

  • By blocking all incoming SQL queries from external sources
  • By encrypting SQL queries to prevent tampering
  • By restricting database access to authorized users only
  • By sanitizing user inputs before executing SQL queries
DB2 handles SQL injection attacks by sanitizing user inputs before executing SQL queries. SQL injection is a common technique used by attackers to manipulate database queries by inserting malicious SQL code into input fields. By sanitizing inputs, DB2 ensures that any potentially harmful characters or commands are escaped or removed, thus preventing the injection of unauthorized SQL code. This approach helps to mitigate the risk of SQL injection attacks and safeguard the integrity and security of the database. 

What is dynamic SQL statement caching in DB2, and how does it enhance security?

  • Decreases database size by compressing cached SQL statements
  • Enhances security by preventing unauthorized access to cached SQL statements
  • Improves performance by storing frequently executed SQL statements
  • Reduces redundant compilation of SQL statements
Dynamic SQL statement caching in DB2 refers to the process of storing frequently executed SQL statements in a cache memory. This feature improves performance as the database engine doesn't need to recompile these statements every time they are executed. Furthermore, it indirectly enhances security by reducing the exposure of SQL statements to potential attackers. Since the cached statements are already compiled and optimized, there is less risk of attackers exploiting vulnerabilities in the compilation process to execute malicious code or gain unauthorized access to the database. 

How does a materialized view differ from a regular view in DB2?

  • Materialized views are physically stored on disk, while regular views are not
  • Materialized views are updated automatically when the underlying data changes, while regular views are not
  • Materialized views can be indexed for faster query performance, while regular views cannot
  • Materialized views can contain joins across multiple tables, while regular views cannot
A materialized view in DB2 is a database object that contains the results of a query and is physically stored on disk, allowing for faster query performance. Unlike regular views, which are virtual and only stored as a predefined query, materialized views are materialized or precomputed and updated automatically when the underlying data changes, ensuring data consistency. 

What role does log shipping play in disaster recovery for DB2 databases?

  • It automatically switches to a secondary server in case of primary server failure
  • It compresses log files for efficient storage and transfer
  • It ensures continuous data replication to a remote location
  • It provides point-in-time recovery by applying logs to a standby database
Log shipping in disaster recovery ensures that changes made to the primary DB2 database are replicated to a standby database in real-time or near real-time. This replication allows for point-in-time recovery by applying transaction logs to the standby database, ensuring minimal data loss in the event of a disaster. 

How does data compression impact database performance in DB2?

  • Degrades Performance
  • Depends on Data Type
  • Improves Performance
  • No Impact on Performance
Data compression in DB2 can improve database performance by reducing the amount of data that needs to be stored, transferred, and processed. With smaller data footprints, compression can lead to faster query execution times, reduced I/O operations, and improved memory utilization, resulting in overall performance enhancements. However, the impact of compression on performance may vary depending on factors such as the compression algorithm used, data characteristics, and workload patterns. Properly configured compression strategies can effectively balance storage savings with performance considerations in DB2 environments. 

How does Visual Explain assist in identifying potential bottlenecks in query execution?

  • Estimating execution time
  • Highlighting high-cost operations
  • Providing SQL code
  • Visualizing query plan
Visual Explain assists in identifying potential bottlenecks in query execution by highlighting high-cost operations. By visually representing the query execution plan, it makes it easier to identify operations that are resource-intensive or time-consuming, thus allowing for optimization of the query for better performance. 

What considerations should be made when using views in a distributed DB2 environment?

  • All of the above
  • Data consistency
  • Network latency
  • Security concerns
In a distributed DB2 environment, several considerations need to be made when using views. Network latency can impact performance, so optimizing network connectivity is crucial. Data consistency across distributed systems is essential to ensure accurate results. Security concerns such as data encryption and access control must be addressed to prevent unauthorized access to sensitive information. Considering all these factors is essential for efficient and secure operations in a distributed DB2 environment. 

Scenario: A developer needs to create a relationship between two tables in DB2, ensuring referential integrity. Which constraint should they implement?

  • Check Constraint
  • Foreign Key Constraint
  • Primary Key Constraint
  • Unique Constraint
A Foreign Key Constraint establishes a relationship between two tables, ensuring referential integrity by enforcing that values in one table must exist in another table's specified column. This constraint maintains the integrity of the relationship between tables. 

Database Services in DB2's architecture are responsible for ________.

  • Data manipulation and query processing
  • Data storage management
  • Database backup and recovery
  • Database security
Database Services in DB2 architecture primarily handle data storage management tasks such as organizing data on disk, managing buffer pools, and allocating storage space efficiently to optimize performance and resource utilization.