Why would a flat file system not be the optimum choice for data storage for an online shopping cart application?

A flat file system is inherently designed to store data in a simple, text-based format without any complex structure, making it less suitable for applications requiring multiple users to access and manipulate data simultaneously, such as an online shopping cart application. This type of system lacks built-in mechanisms to handle concurrent transactions and user access, which can result in data conflicts and inconsistencies.

In an online shopping scenario, several customers might be attempting to access and update the shopping cart at the same time. A flat file system doesn't provide the necessary features, like locking mechanisms or multi-user support, to ensure that one user's changes do not overwrite or conflict with another's. This limitation can lead to lost data or errors, negatively impacting the user experience and overall functionality of the application.

In contrast, database management systems (DBMS) are designed to efficiently handle multiple concurrent users and provide the necessary stability and integrity for data storage in dynamic environments, making them a much better choice for applications like online shopping carts.