The Ultimate Guide to High Availability with MariaDB

ACID: Concurrency Control with Transactions

You are viewing an old version of this article. View the current version here.

This article is currently incomplete

Database requests happen in linear fashion, one after another. When many users are accessing a database, or one user has a related set of requests to run, it becomes important to ensure that the results remain consistent. To achieve this, you use transactions, which are groups of database requests that are processed as a whole. Put another way, they are logical units of work.

To ensure data integrity, transactions need to adhere to four conditions: atomicity, consistency, isolation and durability (ACID).

Atomicity

Atomicity means the entire transaction must complete. If this is not the case, the entire transaction is aborted. This ensures that the database can never be left with partially completed transactions, which lead to poor data integrity. If you remove money out of one bank account, for example, but the second request fails and the system cannot place the money in another bank, both requests must fail. The money cannot simply be lost, or taken from one account without going into the other.

Comments

Comments loading...
Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.