ACID (Atomicity, Consistency, Isolation, Durability) is a set of properties of database transactions intended to guarantee validity even in the event of errors, power failures, etc.
In the context of databases, a sequence of database operations that satisfies the ACID properties, and thus can be perceived as a single logical operation on the data, is called a transaction.
For example, a transfer of funds from one bank account to another involves debiting from one account and crediting to another, and this whole process is a single transaction.
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.
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.
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.
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.
Taking you to the next exercise in seconds...
Want to create exercises like this yourself? Click here.
No hints are availble for this assesment
Answer is not availble for this assesment
Loading comments...