Why database choice impacts architecture in HLD - Quick Recap

Recall & Review

beginner

What is one main reason the choice of database affects system architecture?

Different databases have unique ways of storing and retrieving data, which influences how the system is designed to handle data flow and performance.

intermediate

How does a relational database differ from a NoSQL database in terms of architecture impact?

Relational databases use structured tables and enforce relationships, requiring strict schema design, while NoSQL databases offer flexible schemas and scale horizontally, affecting how data models and scaling strategies are planned.

intermediate

What is CAP theorem and why is it important when choosing a database?

CAP theorem states a system can only guarantee two of three: Consistency, Availability, and Partition tolerance. This affects architecture decisions based on which properties are prioritized.

advanced

Why does database scalability influence system architecture?

If a database scales well horizontally, the architecture can distribute load across many servers, improving performance and fault tolerance. Poor scalability may require more complex caching or sharding strategies.

advanced

How can database consistency models impact application design?

Strong consistency requires waiting for all nodes to agree on data, which can slow responses but ensures accuracy. Eventual consistency allows faster responses but needs the application to handle temporary data differences.

Which database type typically requires a fixed schema and enforces relationships?

A Graph database

B NoSQL document store

C Key-value store

D Relational database

Relational databases use tables with fixed schemas and enforce relationships through keys.

What does the CAP theorem say a distributed system cannot guarantee all at once?

A Concurrency, Accessibility, Persistence

B Capacity, Accuracy, Performance

C Consistency, Availability, Partition tolerance

D Cache, Analytics, Privacy

CAP theorem states a system can only guarantee two of Consistency, Availability, and Partition tolerance.

Which database feature most directly affects how easily a system can handle more users?

A Scalability

B Encryption

C Backup frequency

D Data type support

Scalability determines how well a database can grow to support more users or data.

Eventual consistency means:

A Data is always immediately consistent

B Data updates will be visible everywhere after some time

C Data is never consistent

D Data is consistent only on weekends

Eventual consistency means data changes propagate and become consistent after a delay.

Choosing a NoSQL database often means:

A Flexible schema and easier horizontal scaling

B Strict schema and vertical scaling only

C No support for distributed systems

D No support for large data volumes

NoSQL databases usually allow flexible schemas and scale horizontally well.

Explain how the choice between relational and NoSQL databases impacts system architecture.

Think about how data is organized and how the system grows.

Describe the importance of CAP theorem in designing distributed database systems.

Consider what happens when parts of the system can't communicate.