In a relational database, what does a one-to-many relationship imply?
- Each record in the "many" table can be related to multiple records in the "one" table
- Each record in the "many" table can be related to only one record in the "one" table
- Each record in the "one" table can be related to multiple records in the "many" table
- Each record in the "one" table can be related to only one record in the "many" table
A one-to-many relationship in a relational database implies that each record in the "one" table can be related to multiple records in the "many" table. This type of relationship is fundamental in database design and is often represented using foreign keys.
_______ is the process of reorganizing data into separate sections to improve manageability and performance.
- Denormalization
- Normalization
- Partitioning
- Sharding
Partitioning is the process of reorganizing data into separate sections or partitions. This technique helps in managing large datasets more efficiently, improving query performance, and optimizing data storage and retrieval processes.
What are the key differences between a fact table and a transactional table in a relational database?
- Fact tables are used for online transaction processing (OLTP), while transactional tables are used for online analytical processing (OLAP)
- Fact tables contain aggregated data, while transactional tables store detailed, raw data
- Fact tables have a primary key, while transactional tables have foreign keys
- Fact tables store current data, while transactional tables store historical data
Fact tables in a relational database store aggregated data, often derived from transactional tables. Transactional tables, on the other hand, store detailed, raw data. Recognizing these differences is essential for efficient database design and querying in both OLAP and OLTP environments.
In Slowly Changing Dimensions (SCD), Type 4 utilizes an _______ table to store historical changes.
- Archive
- Audit
- Historical
- Snapshot
In Slowly Changing Dimensions (SCD) Type 4, a "Historical" table is used to store historical changes. This allows tracking changes over time while maintaining the current data in the main table. This type is beneficial when it's essential to preserve a complete history of changes.
What are the key considerations when designing a conceptual schema?
- Data integrity, simplicity, and normalization
- Data redundancy, complexity, and denormalization
- Normalization, redundancy, and write efficiency
- Query performance, redundancy, and complexity
Key considerations when designing a conceptual schema include maintaining data integrity, ensuring simplicity, and applying normalization techniques. These factors contribute to a robust and efficient database design.
In database modeling, a _______ key is a key that uniquely identifies a record within a table.
- Composite
- Foreign
- Primary
- Secondary
In database modeling, a primary key is a key that uniquely identifies a record within a table. It serves as the unique identifier for each row and ensures data integrity by preventing duplicate or null values in this key field.
Which type of data does a dimension table primarily contain?
- Descriptive data
- Metadata
- Numerical data
- Transactional data
A dimension table primarily contains descriptive data that provides context to the numerical values stored in the fact table. Dimension tables typically include attributes such as customer name, product category, time period, etc. These attributes are used to slice and dice the data in the fact table for analysis.
In terms of architecture, how are Data Warehouses and Data Marts typically implemented differently?
- Data Marts use a centralized architecture
- Data Marts use a distributed architecture
- Data Warehouses use a centralized architecture
- Data Warehouses use a federated architecture
Data Warehouses are typically implemented with a centralized architecture, where data from various sources is integrated into a single repository. On the other hand, Data Marts often use a distributed architecture, allowing them to be more specialized and independently designed for specific business needs.
What is the primary characteristic of a Star Schema?
- Each dimension table is connected to other dimension tables
- Each dimension table is directly connected to the fact table
- Fact table is absent in the schema
- Fact table is organized in a snowflake pattern
In a Star Schema, the primary characteristic is that each dimension table is directly connected to the fact table. This results in a simple and straightforward structure, making it easier to understand and query data for analytical purposes.
What type of data does a graph database model emphasize?
- Hierarchical data
- Relationship data
- Structured data
- Unstructured data
A graph database model emphasizes relationship data. It is designed to efficiently capture and represent the relationships between entities, making it suitable for scenarios where understanding connections between different data points is crucial.