ACID vs BASE
ACID
ACID is a set of properties that guarantee the reliability and integrity of database transactions, especially in traditional relational database management systems (RDBMS). The properties are:
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Atomicity: A transaction is an indivisible and indivisible unit of work, which either completes entirely or does not execute at all. If any part of the transaction fails, the entire transaction is aborted, and the database state is left unchanged.
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Consistency: A transaction must move the database from one valid state to another valid state, according to all defined rules, constraints, cascades, and triggers. Transactions cannot violate database constraints like unique keys, foreign keys, etc.
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Isolation: Concurrent transactions are isolated from each other, meaning that the intermediate state of a transaction is invisible to other transactions. This prevents dirty reads, non-repeatable reads, and phantom reads.
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Durability: Once a transaction is committed, it will remain committed even in the case of a system failure (e.g., power outage or crash). The results are permanently stored in the database.
ACID properties are essential for systems that require data integrity and consistency, such as banking, finance, and e-commerce applications.
BASE
BASE is a model that prioritizes availability and partition tolerance over consistent behavior in distributed systems, particularly in large-scale web applications and NoSQL databases. The properties are:
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Basically Available: The system guarantees availability, i.e., every request receives a response, although the response could be incomplete or inconsistent with the desired state.
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Soft State: The state of the system may change over time, even without any input from clients, due to eventual consistency mechanisms or background processes.
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Eventual Consistency: The system will eventually become consistent once it stops receiving inputs. The data will converge to a consistent state after a period of time, but the system may show inconsistent data temporarily.
BASE properties are useful in systems where high availability and partition tolerance are more important than strong consistency, such as real-time analytics, content delivery networks, and collaborative applications.
Trade-offs
ACID and BASE represent different trade-offs between consistency and availability in distributed systems, according to the CAP theorem (Consistency, Availability, Partition Tolerance). ACID systems prioritize strong consistency, while BASE systems prioritize availability and partition tolerance.
ACID systems are suitable for applications that require strict data integrity, such as financial transactions or database systems, but may suffer from reduced availability or scalability in distributed environments.
BASE systems are better suited for large-scale distributed systems, where high availability and partition tolerance are more important than strong consistency. However, they may exhibit temporary inconsistencies, which might be acceptable for certain types of applications, such as real-time analytics or collaborative editing tools.
The choice between ACID and BASE depends on the specific requirements of the application, the trade-offs between consistency and availability, and the tolerance for potential data inconsistencies.