Question

If the system makes repeated requests for tuples from the operation at the top of the table, it is called as _________

(a) Demand driven pipeline

(b) Producer driven pipeline

(c) Query driven pipeline

(d) None of the mentioned

I had been asked this question in quiz.

My doubt stems from Evaluation of Expressions topic in chapter Query Processing and Optimization of RDBMS

Answer 1

Correct option is (a) Demand driven pipeline

To explain: If the system makes repeated requests for tuples from the operation at the top of the table, it is called as demand driven pipeline. Each time an operation receives a request for tuples, it computes the next tuple or tuples to be returned and then returns that tuple.