I'm trying to fully understand what counts as a unique permission when working with a large library.
Library structure: Library - Document Set - Folder
Only three SP groups will have access to the library: Owners, Members and Visitors
Permissions will be set as follows:
Library (broken inheritance): Owners (Full Control), Members (Contribute), Visitors (Read)
Document set (inherited from lib.): same as library
Folder (broken inheritance): Owners (Full Control), Members (Contribute), Visitors (Contribute)
After a few years the library will have 20k+ document sets. As long as the SP groups are used to secure the objects in the library will there be any issues with hitting any security boundaries?
This thread: Question on unique permissions count hits on some of the same points but conflicts with the documentation provided by Microsoft.
Note from Microsoft:
"Exceeds list view threshold" or "too many items with unique permissions" error when trying to share or break inheritance
This issue occurs for one of the following reasons:
When a list, library, or folder contains more than 100,000 items, you can neither break permission inheritance nor reinherit permissions on the list, library, or folder. However, you can still break inheritance on the individual items within that list, library, or folder, up to the maximum number of unique permissions.
The supported limit of unique permissions for items in a list or library is 50,000. However, the recommended general limit is 5,000. Making changes to more than 5,000 uniquely permitted items at a time takes longer. Therefore, for large lists, design the list to have as few unique permissions as possible.