Question

What are the function of selection and projection operation?

Answer 1

sorry I didn't know that

Answer 2

Hey !$<b>$

The select operation selects tuples from a relation that satisfy a given condition. The selection is denoted by  lowercase Greek letter  (sigma).

The project operation yields a “vertical” subset of a given relation in contrast to the “horizontal” subset returned  by select operation. The projection lets you select specified attributes in a specified order. Projection is denoted by  Greek letter pi(π).