Multi-dimensional clustering (MDC) in DB2 improves performance by organizing data in ________.
- Clusters
- Dimensions
- Partitions
- Tables
Multi-dimensional clustering (MDC) in DB2 improves performance by organizing data in clusters. MDC allows data to be physically organized in multiple dimensions, enabling efficient retrieval of data based on various criteria, such as range queries, which enhances performance significantly.
Scenario: A company plans to expand its user base, leading to increased data access requests. How can DB2's architecture accommodate this growth without compromising performance?
- Connection Pooling
- Data Partitioning
- Indexing
- Query Optimization
Data Partitioning can help distribute data across multiple physical storage devices or servers, allowing parallel processing of queries and accommodating increased user requests. It enhances scalability by reducing contention for resources and improving overall system performance.
Indexes with INCLUDE columns in DB2 can optimize ________.
- Data retrieval performance
- Data storage efficiency
- Index creation
- Query performance
Indexes with INCLUDE columns in DB2 can optimize query performance. By including additional non-key columns in the index, DB2 can cover more queries, reducing the need to access the base table and improving query performance.
In DB2, data integrity is typically enforced using ________.
- Constraints
- Indexes
- Triggers
- Views
Constraints in DB2 are primarily responsible for enforcing data integrity by specifying rules or conditions that data must adhere to. This ensures that only valid data is entered into the database, contributing to its reliability and accuracy.
Clustering indexes in DB2 are used to improve ________ performance.
- Insertion
- Retrieval
- Sorting
- Update
Clustering indexes in DB2 are used to improve retrieval performance. These indexes arrange the data in the table based on the order of the index keys, which helps in quickly locating and retrieving rows based on specific criteria, thus enhancing retrieval performance.
What are some considerations for optimizing performance when using the LOAD utility in DB2?
- Controlling transaction concurrency, Eliminating data validation, Increasing transaction isolation levels, Simplifying data structures
- Increasing database complexity, Reducing system memory, Disabling logging mechanisms, Avoiding data partitioning
- Optimizing query execution, Adjusting indexing strategies, Balancing workload distribution, Reducing database redundancy
- Properly configuring buffer sizes, Minimizing network latency, Utilizing solid-state drives (SSDs), Employing multi-threading
Optimizing performance when using the LOAD utility in DB2 involves various considerations. These include properly configuring buffer sizes to efficiently manage data transfer, minimizing network latency to expedite communication between the database and external storage, utilizing solid-state drives (SSDs) for faster data access, and employing multi-threading to parallelize the loading process and utilize available system resources effectively.
What is the main advantage of using a common table expression (CTE) over a subquery in DB2?
- CTEs are more efficient than subqueries
- CTEs can be used recursively
- CTEs can only be used once in a query
- Subqueries are more efficient than CTEs
The main advantage of using a CTE over a subquery in DB2 is that CTEs can be used recursively, allowing for more complex and flexible queries. Subqueries cannot achieve this level of recursion.
DB2 allows for the creation of ________ to enforce complex data integrity rules.
- Constraints
- Stored Procedures
- Triggers
- Views
Constraints
What is the purpose of the NOT NULL constraint in DB2?
- NOT NULL constraint allows specifying a default value for a column when NULL is encountered.
- NOT NULL constraint automatically increments the column value when a new row is inserted.
- NOT NULL constraint ensures that a column cannot contain NULL values.
- NOT NULL constraint restricts the insertion of duplicate values in a column.
The NOT NULL constraint in DB2 ensures that a column cannot have NULL values, thereby enforcing data integrity and preventing unexpected behavior in applications that rely on non-null values for certain attributes. This constraint is essential for maintaining data consistency and avoiding errors related to NULL handling.
How does normalization help in reducing redundancy in a database?
- Enhances query performance
- Improves data security
- Increases data storage requirements
- Reduces data duplication
Normalization helps in reducing redundancy by organizing data into multiple related tables, thereby minimizing duplicate data entries. This leads to efficient storage utilization and improves data consistency and integrity.