Data _______ is a technique used to maintain consistency and accuracy of data in a database.
- Encryption
- Indexing
- Normalization
- Validation
Data Validation is a technique used to maintain consistency and accuracy of data in a database. It involves checking the accuracy and reliability of data entered into the system, ensuring that it meets specific criteria or conditions. This is crucial for data integrity and quality.
What strategies can be employed to ensure data consistency across partitions?
- Consistent hashing
- Eventual consistency
- Two-phase commit protocol
- Vector clocks for timestamp ordering
Strategies like the Two-phase commit protocol can be employed to ensure data consistency across partitions in distributed databases. This involves a coordinated approach to commit or abort transactions across all nodes, ensuring that data remains consistent even in a distributed environment.
What does "Forward Engineering" refer to in the context of database design?
- Creating a conceptual data model
- Generating a database schema from a higher-level model
- Modifying an existing database schema
- Optimizing a database for performance
In database design, "Forward Engineering" involves generating a database schema from a higher-level model, such as a conceptual data model. This process moves from an abstract representation to a concrete implementation, helping in the actual creation of the database structure.
What is the purpose of Slowly Changing Dimensions (SCD) in data modeling?
- To capture changes to dimension data over time
- To design complex queries
- To enforce data integrity constraints
- To speed up data retrieval from databases
Slowly Changing Dimensions (SCD) in data modeling are used to capture changes to dimension data over time. They allow for the tracking of historical data and help maintain a history of changes to dimensional attributes, which is crucial for analysis and reporting purposes.
One technique used in denormalization is the creation of _______ tables to store precomputed results.
- Aggregate
- Lookup
- Metadata
- Staging
In denormalization, the creation of Aggregate tables is a technique to store precomputed results. These tables contain summarized data, reducing the need for complex calculations during query execution and improving overall performance.
Scenario: A financial institution wants to analyze customer behavior patterns, including changes in account status and product subscriptions. Which Slowly Changing Dimensions (SCD) technique would you suggest and how would you implement it?
- Type 1 SCD
- Type 2 SCD
- Type 3 SCD
- Type 4 SCD
For analyzing customer behavior patterns, including changes in account status and product subscriptions, Type 3 Slowly Changing Dimensions (SCD) would be suggested. This type involves creating a separate table to store only the changed attributes, reducing redundancy while still providing historical information for analysis.
The relationship between two entities can be either _______ or _______.
- Many-to-Many
- Many-to-One
- One-to-Many
- One-to-One
The relationship between two entities in a database can be either One-to-One, One-to-Many, Many-to-One, or Many-to-Many. Understanding these relationship types is essential for designing a well-structured database.
The structure of data in a column-family store allows for efficient _______.
- Data encryption
- Horizontal scaling
- Relational mapping
- Vertical scaling
The structure of data in a column-family store allows for efficient horizontal scaling. Column-family stores, like Apache Cassandra, distribute data horizontally across multiple nodes, enabling them to handle large amounts of data and traffic effectively. This scalability is crucial for systems with growing datasets and user loads.
Scenario: During the development of a new database application, the requirements undergo frequent changes. How can the team utilize Forward and Reverse Engineering processes to adapt to these changes efficiently?
- Rely on Forward Engineering only
- Rely on Reverse Engineering only
- Use Forward Engineering for initial development, then Reverse Engineering for changes
- Use Reverse Engineering to establish a baseline, then Forward Engineering for changes
Utilizing Reverse Engineering to establish a baseline allows the team to adapt to changes efficiently by understanding the existing structure. Subsequent changes can then be implemented using Forward Engineering to maintain consistency and alignment with evolving requirements.
A relationship where each occurrence in one entity must have a corresponding occurrence in another entity is called _______ relationship.
- Many-to-many
- Many-to-one
- One-to-many
- One-to-one
A relationship where each occurrence in one entity must have a corresponding occurrence in another entity is called a one-to-many relationship. This implies that each entity in the first table can be associated with multiple entities in the second table, but each entity in the second table is associated with only one entity in the first table.
Which tools are commonly used for collaboration in data modeling?
- Google Docs
- Microsoft Excel
- Online Data Modeling Platforms
- Pen and Paper
Commonly used tools for collaboration in data modeling include online data modeling platforms. These platforms provide a centralized space for team members to work together, share ideas, and create and modify data models in real-time.
How do dictionary-based compression algorithms work?
- By removing unnecessary whitespace
- By replacing repeated sequences with references to a dictionary
- By sorting the data before compression
- By using mathematical formulas to represent data
Dictionary-based compression algorithms work by identifying repeated sequences in the data and replacing them with references to a dictionary. This dictionary contains commonly occurring patterns or phrases, and their references help in reducing the overall size of the compressed data. This technique is efficient for repetitive data structures and patterns.