Which ACID Property Requires "All or Nothing" Transaction?

A.

Atomicity requires that each transaction is "all or nothing": if one part of the transaction fails, the entire transaction fails, and the database state is left unchanged.

For CISA exam you should know below information about ACID properties in DBMS: Atomicity - Atomicity requires that each transaction is "all or nothing": if one part of the transaction fails, the entire transaction fails, and the database state is left unchanged.

An atomic system must guarantee atomicity in each and every situation, including power failures, errors, and crashes.

To the outside world, a committed transaction appears (by its effects on the database) to be indivisible ("atomic"), and an aborted transaction does not happen.

Consistency - The consistency property ensures that any transaction will bring the database from one valid state to another.

Any data written to the database must be valid according to all defined rules, including but not limited to constraints, cascades, triggers, and any combination thereof.

This does not guarantee correctness of the transaction in all ways the application programmer might have wanted (that is the responsibility of application-level code) but merely that any programming errors do not violate any defined rules.

Isolation - The isolation property ensures that the concurrent execution of transactions results in a system state that would be obtained if transactions were executed serially, i.e.

one after the other.

Providing isolation is the main goal of concurrency control.

Depending on concurrency control method, the effects of an incomplete transaction might not even be visible to another transaction.

[citation needed] Durability - Durability means that once a transaction has been committed, it will remain so, even in the event of power loss, crashes, or errors.

In a relational database, for instance, once a group of SQL statements execute, the results need to be stored permanently (even if the database crashes immediately thereafter)

To defend against power loss, transactions (or their effects) must be recorded in a non-volatile memory.

The following were incorrect answers: Consistency - The consistency property ensures that any transaction will bring the database from one valid state to another.

Any data written to the database must be valid according to all defined rules, including but not limited to constraints, cascades, triggers, and any combination thereof.

This does not guarantee correctness of the transaction in all ways the application programmer might have wanted (that is the responsibility of application-level code) but merely that any programming errors do not violate any defined rules.

Isolation - The isolation property ensures that the concurrent execution of transactions results in a system state that would be obtained if transactions were executed serially, i.e.

one after the other.

Durability - Durability means that once a transaction has been committed, it will remain so, even in the event of power loss, crashes, or errors.

The ACID properties are essential characteristics of a transaction in a database management system (DBMS). The four properties are Atomicity, Consistency, Isolation, and Durability. Each property serves a critical function in maintaining the integrity of data within a database.

The ACID property that requires that each transaction is "all or nothing" is Atomicity. Atomicity guarantees that a transaction is treated as a single unit of work and that it is either completed in its entirety or not at all. In other words, a transaction is considered atomic because it cannot be divided into smaller parts.

Atomicity ensures that a database remains in a consistent state, even in the event of a system failure or interruption. If a transaction fails for any reason, the system will roll back the entire transaction to its original state. This means that none of the changes made by the transaction will be applied to the database.

For example, consider a bank transfer transaction. The transaction involves two operations: debiting one account and crediting another account. If either of these operations fails, the transaction will be rolled back, and none of the changes will be applied to the database. This ensures that the database remains in a consistent state, with the account balances reflecting the correct values.

In summary, Atomicity is the ACID property that requires that each transaction is "all or nothing." It guarantees that a transaction is treated as a single unit of work and that it is either completed in its entirety or not at all. This ensures that the database remains in a consistent state, even in the event of a system failure or interruption.