Atomicity, Consistency, Isolation, and Durability are abbreviated as ACID. These properties define the fundamental requirements for a transaction to maintain data integrity in a database. Transactions are operations that change data in a database, and ACID properties ensure that these changes are completed correctly and reliably.
Data consistency in product engineering ensures products function as intended and provide a positive user experience. For instance, if a customer purchases a product on an e-commerce platform and the system doesn’t update the inventory, they can receive the incorrect goods or cancel their transaction. The customer experience would suffer, and the business’s reputation would suffer.
To guarantee data consistency, reliability, and accuracy, it is crucial for product engineering to comprehend and implement ACID features in databases. It can assist product managers, and developers in building reliable, resilient products that satisfy user demands and expectations.
Atomicity: Refers to the requirement that a transaction be treated as a single, unified unit of work. A transaction can comprise one or more database operations but fails simultaneously. If any operations fail, the entire transaction must be rolled back to restore the database to its previous state.
Consistency: Consistency ensures that a transaction moves the database from one consistent state to another. It means that any constraints or rules defined in the database must be followed, and the database remains valid even if errors or system failures occur. For instance, if a transaction involves updating a bank account’s balance, the balance should always reflect the correct amount, regardless of any intermediate errors.
Isolation: Isolation prevents concurrent transactions from interfering with one another. Multiple transactions can run concurrently, but each transaction must act as if it is the only one running in the system.
This means that a transaction should not be able to see another transaction’s intermediate state, and changes made by one transaction should not affect the outcome of another. Isolation levels such as Read Committed, Repeatable Read, and Serializable provide varying isolation guarantees.
Durability: When a transaction is committed, the changes must persist even if the system fails, crashes, or loses power. This is typically accomplished by using transaction logs, which record all changes made by a transaction before they are applied to the database.
In the event of a failure, these logs can be used to restore a consistent state to the database.
Implementing ACID properties in databases necessitates careful database system design and implementation. Some of the most critical factors to consider when ensuring ACID compliance are as follows:
Transaction management: As a fundamental concept, the database system must support transactions and provide mechanisms for initiating, committing, and rolling back transactions. The system must also ensure that transactions are atomic, meaning that all operations in a trade either succeed or fail simultaneously.
Consistency check: The database system must enforce consistency constraints, such as data type checks, referential integrity, and business rules. The system must validate data before committing changes to ensure the database remains consistent.
Isolation levels: The database system must provide different isolation levels to support concurrent transactions. The system must ensure that transactions are separated so that the outcome of one does not affect the outcome of another.
Transaction logs: The database system must keep transaction logs to ensure durability. The registers must record all changes made by a transaction before they are applied to the database, and in the event of a failure, the system must be able to use these logs to restore the database to a consistent state.
Backup and recovery: If something goes wrong, the database system must include mechanisms for backing up and recovering the database. This may entail performing regular database backups, keeping redundant copies of the data, or employing high-availability techniques such as replication and clustering.
To implement ACID properties in a database system, you can use a database management system (DBMS) that supports these properties. Popular DBMSs that support ACID properties include SQL platforms, Oracle, Microsoft SQL Server, PostgreSQL, and MySQL. Additionally, you can design your database schema and application code to ensure that transactions adhere to the ACID properties. For example, you can use stored procedures and triggers to enforce constraints and ensure that trades are executed atomically. Finally, you can test your application thoroughly to ensure it behaves correctly under various failure scenarios.