In high availability setups, the primary goal is to minimize ________ in case of a system failure.
- Data corruption
- Downtime
- Network latency
- Performance degradation
High availability setups aim to minimize downtime in case of system failure. Downtime refers to the period when a system is unavailable or inaccessible, which can result in significant losses for businesses.
Log shipping in disaster recovery involves periodically copying ________ from the primary to the standby server.
- Data files
- Entire database
- Log files
- Transaction logs
Log shipping in disaster recovery typically involves copying transaction logs from the primary database server to the standby server. These transaction logs contain a record of all changes made to the database, allowing the standby server to maintain a synchronized copy of the primary database for disaster recovery purposes.
A DBA notices a decline in query performance in a DB2 database. What steps can they take using the Runstats and Reorg utilities to improve performance?
- Analyze query execution plans and identify any missing or outdated statistics on tables and indexes
- Disable logging for the affected tables and indexes to reduce overhead during query execution
- Drop and recreate all indexes on the tables to eliminate fragmentation and improve query performance
- Increase buffer pool sizes and adjust memory configuration settings to allocate more resources for query processing
Analyzing query execution plans helps identify areas where statistics are outdated or missing, which can lead to poor query performance. Running Runstats updates these statistics, providing the query optimizer with accurate information for generating efficient execution plans. Reorganizing the database using the Reorg utility helps to defragment tables and indexes, improving data locality and access efficiency, thus further enhancing query performance. Adjusting buffer pool sizes and memory configurations may optimize memory usage but may not directly address the root cause of performance degradation related to outdated statistics or fragmented data. Disabling logging for tables and indexes is not a recommended practice as it compromises data integrity and recoverability.
In what scenarios would denormalization be recommended in a database design?
- Enhance data integrity
- Improve query performance
- Increase data consistency
- Reduce redundancy
Denormalization is recommended in scenarios where there is a need to improve query performance by reducing the number of joins required to retrieve data, even at the cost of redundancy and potentially sacrificing some data integrity and consistency.
The output of a user-defined function in DB2 can be used as a ________ in SQL statements.
- Column
- Parameter
- Subquery
- Variable
The output of a user-defined function in DB2 can be used as a column in SQL statements. This means that the result returned by the function can be treated as a regular column value and utilized in various SQL operations, including SELECT, INSERT, UPDATE, and DELETE statements. Utilizing user-defined functions in this manner enhances the flexibility and power of SQL queries, allowing developers to leverage custom logic within their database operations.
What are the different installation options available in DB2?
- GUI Installation
- Console Installation
- Silent Installation
- Custom Installation
DB2 installation offers various options including GUI for graphical interface guided installation, Console for command-line installation, Silent for unattended installation, and Custom for tailored installations.
In DB2, user-defined functions are typically stored in ________.
- Indexes
- Packages
- Schemas
- Tables
In DB2, user-defined functions are typically stored in Packages. Packages provide a way to group related functions and procedures together, making it easier to manage and deploy them within the database.
The ROLLFORWARD command in DB2 is used to ________.
- Recover the database
- Rollback transactions
- Apply database changes
- Restore the database
The correct option is Option 3: Apply database changes. The ROLLFORWARD command in DB2 is used to apply database changes that were recorded in the transaction log files since the last backup was taken. It's essential for maintaining database integrity and consistency during recovery processes.
The INSERT INTO statement in SQL is used to ________ new records into a database table.
- Add
- Append
- Create
- Insert
The INSERT INTO statement in SQL is used to add new records or rows into a table. It allows you to specify the values for each field or column you want to insert into the table.
Which normal form allows multivalued attributes?
- First Normal Form (1NF)
- Fourth Normal Form (4NF)
- Second Normal Form (2NF)
- Third Normal Form (3NF)
Third Normal Form (3NF)