Why this question is important, because in smart contract that have huge usecase , like wallet by using this technique we can reduce storage fee significantly, like v5 of tonkeeper, in their repo , they said we used shared library, in master chain . But I don't know how they did that , and which process should be carried out to have this facilities.

Database concepts in TON , and how they really works is hard to grasp . Block , smart contract , have id , but what about something like library or specefic cells?