In what cases are side tables used in a database?

Side Tables in a database are used when you need to store additional information that does not fit or is not practical for the main table. For example:

• To store rarely used or large-volume data to avoid loading the main table.
• To separate data based on security or access rights.
• To implement schema extensibility without changing the main structure.

In iOS, for instance, when using Core Data, a Side Table can be used to store metadata or auxiliary data related to the main entity but not requiring constant loading.