How to do a text search on all core data entities?

Question

Objective-C

IOS 9 platform. Entities with string properties are created, the names of the properties of the entities differ from each other. Managed Core Data objects are saved and deleted by standard means. I want to implement search by these properties. The search mechanism is as follows: when I enter a word in the search bar, in response, I should receive objects that contain this word in their properties. What is the best way to do this? Create an index or a separate sqlite database, or can it be implemented in another way? What is the right way to tie all this to the lifecycle of the managed object?
I thought that this is a fairly popular case, and I am surprised by the lack of ready-made libraries. If you have any work done please share. If not, please help me figure out what to do.