Question

define the following projection, selection, union, Cartesian product​

Answer 1

Answer:

The Cartesian Product is also an operator which works on two sets. It is sometimes called the CROSS PRODUCT or CROSS JOIN. It combines the tuples of one relation with all the tuples of the other relation.

Answer 2

Answer:

Operation(Symbols) Purpose

Select(σ) The SELECT operation is used for selecting a subset of the tuples according to a given selection condition

Projection(π) The projection eliminates all attributes of the input relation but those mentioned in the projection list.