Backend frameworks/platforms like Node.js(EcmaScript) and Django(Python).

for example, I do think that calling SomeClass.objects.all().filter() will loop the whole data ( O(N) Linear Way) until it gets the full results . I think it would be okay if the data is kept small up to medium but for large data; I don't think so. Imagine million of these data and thousands of requests per day. How can We handle those request in an efficient way

• I can call raw SQL in Django (suppose I'm working with Django) if I need, that can allow for more efficient request with large amount of data

• I believe in that too.However if I need to make that, first I need to organize the data in sql appropriately ( using Data Structures techniques like Hash Tables or Balanced Binary Tree) then I can quickly retrieve them later using Algorithms. What I'm asking is " Am I thinking Right?" "is what I want to accomplish is right and achievable ?" " Do Big Companies implement their own DS and Algorithms in that way ?" I've seen many people teaching DS and Algorithms separately and talk a lot about them and their power. But I've never seen both of them discussed and implemented in any framework by Teachers!!

From What I see , I started to believe that No Body Really care and I don't know Why?

• Being out of college with CS, and always only worked my way around DS & Algorithms mostly through Online Judges I don't know how to merge my knowledge into this?

I hope my question doesn't sound vague or irrelevant I'm in learning phase, so please ignore any immaturity. Any explanation/advice/guidance is appreciated.