1.

What is the function of select and project operation ?

Answer»

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



Discussion

No Comment Found

Related InterviewSolutions