CompTIA DataSys+ (DS0-001)Database FundamentalsHard
A data engineering team is building a data pipeline that processes real-time events. They need a database that can handle extremely high write throughput and low-latency reads for individual records, but where strong consistency across all nodes is not a strict requirement. Which characteristic of NoSQL databases makes them particularly suitable for this scenario?
- AStrict schema enforcement
- BReferential integrity
- CEventual consistency
- DACID compliance
Show answer & explanationAnswer & explanation
Correct answer: C. Eventual consistency
NoSQL databases often prioritize availability and partition tolerance over strong consistency, leading to eventual consistency. This means that data might not be immediately consistent across all nodes after a write, but will eventually become consistent, which is acceptable for scenarios prioritizing high write throughput and low latency over immediate global consistency.
Why the other options are wrong
- A. Strict schema enforcement is characteristic of relational databases, not NoSQL, which typically offers flexible schemas.
- B. Referential integrity is enforced by foreign keys in relational databases, ensuring relationships are valid, which is not the primary focus of this high-throughput, low-latency, eventually consistent scenario.
- D. ACID compliance (Atomicity, Consistency, Isolation, Durability) is a hallmark of relational databases, ensuring strong consistency, which contradicts the 'not a strict requirement' part.
Eventual Consistency
A consistency model in distributed computing that guarantees that if no new updates are made to a given data item, eventually all accesses to that item will return the last updated value.
- Common in NoSQL databases for high availability and scalability.
- Data may not be immediately consistent across all nodes.
- Sacrifices immediate consistency for performance and availability (part of CAP theorem).
Memory trick: Eventually, all data will agree, but not always at once.