Non-Repeatable Read

A non-repeatable read occurs in a database when a transaction reads the same data multiple times and finds that it has changed between reads due to another transaction's updates. Imagine checking a stock price, then checking again later and seeing a different price because someone else updated it in the meantime. This phenomenon can lead to inconsistencies, especially in financial or critical applications. It highlights how concurrent transactions can interfere with each other, causing data to appear different across multiple reads within the same process.