Oracle SDE 1 interview questions

How did Linked List came in existence.. What was the need for the concept of Linked List to establish? (Beautiful question, linked it with fragmentation in computer memory)

Question started with generating a basic query given the database, with join and filter based on criteria. Then interviewer asked to implement a function that would do excat same things on any programming language i am comfortable with proper assumtions on which structure you would use for tables and how would you extend to perform this query as well.