All required operations are performed

[mahbubamim]

A database transaction is a logical unit of work that consists of one or more operations (such as read, write, update, or delete) performed on a database. Transactions ensure that data is processed reliably and consistently, even in the event of system failures, errors, or concurrent access. They are fundamental to maintaining data integrity in both relational and non-relational databases.

ACID Properties
The reliability of transactions is defined by the ACID properties:

Atomicity: Ensures that all operations within a transaction are completed successfully. If any part of the transaction fails, the entire transaction is rolled back, leaving the database unchanged.

Consistency: Ensures that a transaction brings the database from one valid state to another. The integrity constraints of the database are preserved before and after the transaction.

Isolation: Ensures that multiple transactions occurring simultaneously do not interfere with each other. Intermediate results of one transaction are not visible to other transactions until it is committed.

Durability: Once a transaction is committed, its changes jordan phone number list are permanent, even in the case of system failures or crashes.

Transaction Lifecycle
A typical transaction goes through the following stages:

Begin: The transaction starts and the system keeps track of all operations.

Execute: .

Commit: If all operations succeed, the transaction is committed, and changes are saved.

Rollback: If an error occurs, the transaction is rolled back, and all changes are undone.

Types of Transactions
Implicit Transactions: Automatically started by the system in response to certain SQL commands.

Explicit Transactions: Manually defined by the user using commands like BEGIN TRANSACTION, COMMIT, and ROLLBACK.

Nested Transactions: Transactions within transactions, where only the outermost commit permanently saves the changes.

Concurrency Control
To manage multiple transactions occurring simultaneously, databases implement concurrency control mechanisms such as locking, timestamp ordering, and multiversion concurrency control (MVCC). These prevent problems like dirty reads, non-repeatable reads, and phantom reads.

Importance in Real-World Applications
Transactions are crucial in applications such as banking, e-commerce, and healthcare, where accurate, consistent, and reliable data processing is essential. For example, in banking, transferring money from one account to another involves debiting and crediting—both actions must succeed or fail together to maintain balance consistency.

Conclusion
Database transactions are vital for ensuring data reliability, integrity, and consistency. By following the ACID principles, they allow systems to function correctly even under high concurrency and unexpected failures