So i have this school project, i need to make a database design for a gym, which should be easy.

So i wanted to add the reputation feature from nulled so idk people can leave a rep for each other or something like that ...

But it got me wondering how does nulled keep track of all the reputation that people leave to each other?  like does it has only one table for that.

if thats the case how is it so fast cuz it has like 2 milions members and keeping the track of reputation from all of them is to much and nulled does it so fast...

if each member leaves two reputation to each other that would make it 4 milion recods .... lets say now i need all my reputation... it would have to go through all the 4 milion records 

Idk if im allowed to ask this question but if anyone could explain.

Thank You For Taking The Time To Read This

https://www.codepile.net/pile/kRG3lBR1

1 Sorry codebin didnt work
2) im trying to add a class to each row in a list for every array element which i render
3) error i get : Too many re-renders. React limits the number of renders to prevent an infinite loop.