What are derived attributes, and why are they used in database design?
- Attributes that are mandatory
- Attributes that are not essential
- Attributes that can be calculated or derived from other attributes
- Attributes with no relation to other attributes
Derived attributes in database design are those that can be calculated or derived from other attributes in the database. They are used to avoid data redundancy and improve data accuracy by ensuring that certain values are always up-to-date based on the values of other attributes.
How does partitioning contribute to storage optimization in distributed databases?
- Centralizing data storage
- Distributing data across multiple nodes
- Implementing stronger encryption
- Increasing data redundancy
Partitioning in distributed databases involves distributing data across multiple nodes. This contributes to storage optimization by allowing parallel processing, reducing load on individual nodes, and improving overall system performance. It facilitates efficient data management in large-scale distributed environments.
A manufacturing company wants to calculate the average production output per factory location. Which data modeling technique would you recommend for this scenario?
- Entity-Relationship Diagram
- Fact and Dimension Tables
- Snowflake Schema
- Star Schema
To calculate the average production output per factory location, the recommended data modeling technique is to use Fact and Dimension Tables. This approach involves creating a fact table containing production data and dimension tables providing details about factory locations, enabling efficient analysis.
What are clustering techniques used for in relational schema design?
- Creating composite keys
- Grouping related tables together on disk
- Implementing referential integrity
- Reducing data redundancy
Clustering techniques in relational schema design involve grouping related tables together on disk. This can enhance query performance by minimizing disk I/O when retrieving data from interconnected tables in a query.
A _______ constraint is used to ensure that a column value meets specific criteria.
- Check
- Foreign
- Primary
- Unique
Detailed A check constraint is used to ensure that a column value meets specific criteria or conditions. This helps in maintaining data accuracy and consistency by defining rules that must be satisfied for data in a column.