CompTIA DataSys+ (DS0-001)Database FundamentalsHard
A database administrator is setting up a new database system for a highly available, globally distributed application. The application needs to handle millions of simultaneous users and tolerate node failures without data loss. Data consistency is important but can be eventually consistent, meaning that updates might not be immediately visible across all replicas but will propagate over time. Which architectural principle is being prioritized for this database system?
- AACID properties
- BBASE properties
- CReferential integrity
- DTwo-phase commit
Show answer & explanationAnswer & explanation
Correct answer: B. BASE properties
BASE (Basically Available, Soft state, Eventually consistent) properties are characteristic of many NoSQL databases designed for high availability and scalability in distributed systems, where immediate consistency (ACID) is sacrificed for availability and partition tolerance. The description of 'eventually consistent' directly points to BASE.
Why the other options are wrong
- A. ACID properties (Atomicity, Consistency, Isolation, Durability) prioritize strong consistency and reliability, often at the expense of availability and partition tolerance in distributed systems.
- C. Referential integrity ensures relationships between tables are valid, a concept primarily within relational databases and not a high-level architectural principle for distributed consistency models.
- D. Two-phase commit is a protocol used to achieve atomicity in distributed transactions, ensuring all or none of the nodes commit, which is a mechanism for strong consistency, not eventual consistency.
BASE Properties
An acronym (Basically Available, Soft state, Eventually consistent) that describes the properties of many NoSQL databases, prioritizing availability and partition tolerance over strict consistency.
- Basically Available: The system guarantees availability.
- Soft state: The state of the system can change over time, even without input.
- Eventually consistent: Data will become consistent across all replicas over time, but not immediately.
Memory trick: ACID is for banks, BASE is for web-scale!