ACID vs. BASE Database Transaction Models
Learn to choose between ACID and BASE models for data consistency and availability in System Design.
Handling data correctly is one of the most critical responsibilities in building any application.
When a user transfers money or books a flight, the underlying database must ensure the operation completes perfectly or not at all, maintaining data integrity. However, in large-scale distributed systems that prioritize availability for millions of users, enforcing such strict rules can create bottlenecks.
This fundamental trade-off between consistency and availability is a central challenge that many candidates face in System Design interviews.
This tension has led to the development of different models for managing data transactions. Understanding these models is essential for making informed architectural decisions that align with our application’s specific needs.
Let’s start with the transaction models.
Transaction models
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For example, a bank transfer involves two operations: debiting one account and crediting another. These two actions must be treated as a single, indivisible unit. If either one fails, the entire transaction must be rolled back. Transaction guarantees are the rules that a database follows to ensure data remains reliable and accurate, even when multiple users perform operations simultaneously.
These guarantees are not one-size-fits-all.
A financial system processing payments requires absolute correctness, where even a momentary error is unacceptable. In contrast, a social media platform can tolerate a slight delay in updating a “like” count across all servers to ensure the service remains available to millions of users.
This difference in priorities leads us to two contrasting models:
The choice between these models ...