A retail company wants to analyze its sales data. It has a fact table containing sales revenue, quantity sold, and discounts applied. What type of information would you expect to find in the corresponding dimension tables?
- Customer information, Product details, Time dimensions
- Employee details, Vendor information, Geographical data
- Inventory details, Market trends, Employee information
- Warehouse details, Shipping information, Payment methods
In the context of a retail company's sales data, corresponding dimension tables would likely include information about customers, products, and time. This allows for analysis based on customer preferences, product performance, and temporal trends.
A _______ query language is commonly used for graph traversal and manipulation in graph databases.
- Cypher
- Gremlin
- SPARQL
- SQL
A Cypher query language is commonly used for graph traversal and manipulation in graph databases. Cypher is specifically designed for querying graph data, making it expressive and efficient for tasks such as pattern matching and graph traversal.
Explain the difference between entity integrity and referential integrity.
- Ensuring the accuracy of attribute values in a table
- Ensuring the accuracy of relationships between tables
- Ensuring uniqueness of primary key values in a table
- Maintaining consistency between foreign key and referenced primary key values
Entity integrity focuses on maintaining the accuracy and uniqueness of attribute values within a single table. It ensures that the primary key values are unique, preventing duplicate or null entries in primary key columns. Referential integrity, on the other hand, maintains consistency between foreign key and referenced primary key values across different tables, ensuring that relationships between tables are valid and accurate.
The concept of slowly changing dimensions is primarily concerned with managing changes in _______ over time.
- Data Structure
- Data Types
- Dimension Attributes
- Dimension Hierarchies
The concept of slowly changing dimensions (SCD) is primarily concerned with managing changes in dimension attributes over time. SCD techniques help capture historical data, allowing analysts to analyze how dimensions evolve and change over different time periods.
In database design, how do you handle recursive relationships between entities?
- Create a new database for each recursive relationship
- Ignore recursive relationships in database design
- Use a foreign key in the same table to establish the relationship
- Use a separate table to represent the recursive relationship
In handling recursive relationships in database design, you typically use a foreign key within the same table to establish the relationship. This involves referencing the primary key of the same table, allowing an entity to be related to itself. It's a common technique for modeling hierarchical structures.
Which type of constraint is commonly used to enforce data integrity at the column level in a relational database?
- CHECK
- FOREIGN KEY
- INDEX
- PRIMARY KEY
The CHECK constraint is commonly used to enforce data integrity at the column level in a relational database. It allows you to define conditions that must be met for the data in a column, ensuring its correctness.
What is the purpose of generalization in database design?
- Combining similar entities into a higher-level entity
- Establishing one-to-one relationships
- Separating dissimilar entities into distinct tables
- Storing duplicate data
Generalization in database design serves the purpose of combining similar entities into a higher-level entity, often referred to as a superclass. This helps in simplifying the data model and promoting reusability.
What is the primary data structure used in document-based modeling?
- Graph
- JSON
- Key-Value Pair
- Table
The primary data structure used in document-based modeling is JSON (JavaScript Object Notation). JSON allows for flexible and hierarchical data representation, making it suitable for storing and retrieving complex data structures. Document databases leverage this format to organize and query data efficiently.
How does version control handle rollback of changes in data models?
- Automatically rolling back to the previous version
- Creating a new branch for each rollback
- Deleting the entire version history
- Manually reverting changes to a specific commit
Version control handles rollback by allowing users to manually revert changes to a specific commit. This ensures flexibility in undoing undesirable modifications and restoring the data model to a previous state while maintaining a record of version history.
Scenario: A multinational e-commerce company wants to implement data partitioning for its product database. How would you advise them on choosing between range-based and hash-based partitioning?
- Hash-based for specific access patterns
- Hash-based for uniform distribution
- Range-based for easy data range queries
- Range-based for even data distribution
When choosing between range-based and hash-based partitioning, hash-based is advised for uniform distribution and to avoid hotspots. Range-based is suitable for queries involving specific data ranges. The decision depends on the access patterns and distribution goals.
What is a common challenge faced when using Key-Value Stores for complex data structures?
- Difficulty in representing relationships between data
- Inefficient for simple data retrieval
- Lack of consistency in data storage
- Limited support for large datasets
A common challenge when using Key-Value Stores for complex data structures is the difficulty in representing relationships between data. Unlike relational databases that excel in handling complex relationships through join operations, Key-Value Stores may face challenges in maintaining such associations directly.
One challenge of using compression techniques in database systems is _______.
- Decreased storage efficiency
- Improved data retrieval speed
- Increased processing overhead
- Limited data security
One challenge of using compression techniques in database systems is the increased processing overhead. Compression and decompression processes require additional computational resources, and striking a balance between storage savings and processing speed is crucial in database design.