A dirty read is a term used in database management to describe a situation where a transaction reads data from a database that has been modified by another transaction, but not yet committed.

This can lead to inaccurate or inconsistent results, as the data being read may not reflect the most up-to-date information. In simpler terms, imagine two users accessing the same database at the same time.

User A makes changes to a record, but has not yet saved those changes.

User B then tries to read that same record before User A has finished making their changes.

In this scenario, User B would be performing a dirty read, as they are accessing incomplete or potentially incorrect data. Dirty reads can occur in multi-user environments where multiple transactions are being processed simultaneously.

While dirty reads can sometimes be useful for certain applications, such as real-time reporting or analytics, they can also lead to data inconsistencies and errors if not managed properly. To prevent dirty reads, database management systems often use mechanisms such as locking, isolation levels, and transaction control to ensure that data is accessed and modified in a controlled and consistent manner.

By understanding the risks and implications of dirty reads, developers and database administrators can implement strategies to maintain data integrity and reliability within their systems.