Subluxation: Partial dislocation of a joint. A complete dislocation is a luxation.
The largest number of items per content database that has been tested on SharePoint Server 2013 is 60 million items, including documents and list items. If you plan to store more than 60 million items in SharePoint Server 2013, you must deploy multiple content databases.
In my scenario, a document library has 3 hierarchies and each hierarchies contains 50 - 100 folders. The number of folders has possible to be 1,000,000 (=100*100*100). Additionally, the terminal folders should have unique role assignments. In straightforward way, it takes more time to add folder and set role assignments to it as the number of created folders increases. The index fragmentation of SharePoint database may cause this problem. I have only idea to execute SQL command to rebuild index for solving this problem, but this is not good method.