Scenario: A database backup in DB2 failed halfway through the process. How can the DBA ensure data consistency and integrity in this situation?
- Manually check each table for inconsistencies and correct them using SQL queries.
- Perform a full database backup again and continue with regular backup schedules.
- Restore the failed backup and apply the remaining transaction logs to bring the database to a consistent state.
- Revert to the last successful backup and apply incremental backups to reach the current state.
If a database backup fails halfway through the process, the DBA should restore the failed backup and apply the remaining transaction logs to bring the database to a consistent state. This ensures that data consistency and integrity are maintained despite the backup failure.
Common thresholds monitored by the Health Monitor may include ________.
- CPU Utilization
- Disk Space
- Memory Usage
- Network Bandwidth
Common thresholds monitored by the Health Monitor may include Memory Usage, as excessive memory consumption can significantly impact database performance and overall system stability.
How does denormalization affect data redundancy in a database?
- Decreases
- Increases
- Maintains
- None
Denormalization increases data redundancy in a database. When denormalizing, redundant data is intentionally introduced to improve query performance by reducing joins. However, this can lead to potential issues such as data inconsistency and increased storage requirements.
The PRIMARY KEY constraint in DB2 ensures ________ integrity.
- Domain
- Entity
- Entity and Referential
- Referential
The PRIMARY KEY constraint in DB2 ensures entity integrity by uniquely identifying each record in a table. This means that each row in the table is uniquely identifiable, preventing duplicate entries and ensuring the integrity of the data model.
What are the key components of a comprehensive disaster recovery plan for a DB2 environment?
- Data encryption and access controls
- RAID storage arrays and disk mirroring
- Redundant network connections and load balancers
- Regular data backups, log shipping, and standby servers
A comprehensive disaster recovery plan for a DB2 environment typically includes regular data backups to ensure data integrity and availability. Log shipping mechanisms are employed to replicate transaction logs to a standby server for point-in-time recovery. Standby servers serve as failover targets in case the primary server becomes unavailable. These components work together to minimize downtime and data loss in the event of a disaster.
What are the benefits of using DB2 Connect for integration with mainframe systems?
- Enhanced security with encryption and authentication features
- Improved performance through optimized communication protocols
- Seamless data access across different platforms with data federation capabilities
- Simplified administration with centralized management capabilities
DB2 Connect facilitates integration between distributed systems and mainframe systems by providing enhanced security features such as encryption and authentication. These features ensure secure communication between distributed systems and mainframes, safeguarding sensitive data during transit.
What is the key difference between INNER JOIN and OUTER JOIN in DB2?
- INNER JOIN retains unmatched rows
- INNER JOIN selects only the matching rows
- OUTER JOIN retains unmatched rows
- OUTER JOIN selects only the matching rows
The key difference lies in how they handle unmatched rows. INNER JOIN returns only the rows that have matching values in both tables, whereas OUTER JOIN returns all rows from both tables, with unmatched rows filled with NULL values.
Visual Explain in DB2 provides a graphical representation of query ________.
- Query plan
- Query result
- Query statistics
- Query syntax
Visual Explain in DB2 provides a graphical representation of the query plan. It helps users understand how DB2 executes their queries, showing details such as access methods, join types, and sorting operations. This visualization aids in optimizing query performance by identifying potential bottlenecks or inefficiencies in the execution plan.
In what situations might you need to resort to using third-party command line tools instead of Control Center or native CLP?
- When managing databases across different platforms
- When needing specialized features not available in native tools
- When performing complex data transformations or analysis tasks
- When requiring real-time monitoring and alerting capabilities
There are instances where third-party command line tools may be necessary, particularly when needing specialized features that are not available in native tools like Control Center or the DB2 Command Line Processor (CLP). These tools often provide advanced functionalities for tasks such as database performance tuning, security auditing, or data encryption, which may be crucial in certain environments. Additionally, third-party tools can offer platform-agnostic solutions for managing databases across heterogeneous environments, ensuring consistency and compatibility.
What is a deadlock in DB2, and how is it resolved?
- A situation where a transaction is blocked by another transaction indefinitely
- A situation where one transaction holds a lock on a resource and another transaction tries to acquire a conflicting lock, resulting in a waiting deadlock
- A situation where two or more transactions are unable to proceed because each is waiting for the other to release a lock
- A situation where two or more transactions are waiting indefinitely for a resource held by each other
Deadlock in DB2 occurs when two transactions hold locks that the other transaction needs to proceed, resulting in a deadlock. It can be resolved by deadlock detection and rollback of one of the transactions involved.