Custom settings for storing app configuration

Custom settings can be used for storing app configuration data that is cached instead of storing in the database.

This helps in quickly accessing the data by the application instead of retrieving from the database.

Where the requirement is for storing small amount of data, its best practice to store it in custom settings instead of creating custom object in database.

For eg, storing a set of country codes that is required by an application.

or storing a set of discounts that can be used in a formula field,

eg: there is a custom settings with fields - Minimum amount spent and Discount allowed.

The formula field can compare the custom object field to this Minimum amount spent field and decide assign discount using the Discount allowed field.

Other use cases:

#1

A shipping application requires users to fill in the country codes for international deliveries. By creating a list setting of all country codes, users have quick access to this data without needing to query the database.

#2

An application displays a map of account locations, the best route to take, and traffic conditions. This information is useful for sales reps, but account executives only want to see account locations. By creating a hierarchy setting with custom checkbox fields for route and traffic, you can enable this data for just the “Sales Rep” profile.

Where used:

Formula fields, validation rules, flows, Apex, and SOAP API can then use this data.

To learn more:

https://developer.salesforce.com/docs/atlas.en-us.apexcode.meta/apexcode/apex_customsettings.htm?search_text=custom%20settings

https://developer.salesforce.com/docs/atlas.en-us.apexcode.meta/apexcode/apex_methods_system_custom_settings.htm?search_text=custom%20settings