DBMS Question
What are ACID properties?

Question

DBMS Question

What are ACID properties?

Accepted Answer

ACID properties are a set of properties that guarantee reliability and consistency in database transactions.

ACID stands for Atomicity, Consistency, Isolation, and Durability.
Atomicity ensures that a transaction is treated as a single unit of work, either all of its operations are executed or none.
Consistency ensures that a transaction brings the database from one valid state to another.
Isolation ensures that concurrent transactions do not interfere with each other.
Durability ensures that once a transaction is committed, its changes are permanent and survive any subsequent failures.
For example, if a bank transfer is made from one account to another, ACID properties ensure that the money is either deducted from the sender's account and added to the receiver's account completely, or the transaction is rolled back if any failure occurs.

Accepted Answer

ACID is a set of properties of database transactions intended to guarantee validity even in the event of errors, power failures, etc.
ACID stands for :
1. Atomicity : All statements of a transaction must succeed completely, or fail completely in each and every situation, including power failures, errors and crashes. Example - Debiting and crediting in a money transfer transaction, both must happen either together or not at all.
2. Consistency : The database must remain in a consistent state after any transaction. Data in the database should not have any changes other than intended after the transaction completion.
3. Isolation : Isolation ensures that concurrent execution of transactions leaves the database in the same state that would have been obtained if the transactions were executed sequentially.
4. Durability :Durability guarantees that once a transaction has been committed, it will remain committed even in the case of a system failure which actually means recording the completed transactions (or their effects) in non-volatile memory.

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