What is the best way to store a large selection from a Magento model?

Question

Magento

How best to implement:
For example, there are 100 users subscribed to category updates.
Each list is different, one has 1,5,9, the other has 5,10,15,20, etc.
So far there are two options:
1st - make one large selection and store in the object while working with it
2nd - fasten some kind of cache, and make the same selection, but save it in the cache
Or maybe there are more adequate options?

Answer 1

Explain in more detail, you are making your own module, do you need an algorithm of work, or what?