Making Vertical Subsets: Project will not be legal relations. The result tables are virtual tables that can be used as input to another relational algebra operation. A projection of a relation is a new relation created by copying one or more the columns from the original relation into a new table. As an example, consider Figure 2-1. The result table (ar- bitrarily called Names_and_numbers) is a projection of the cus- tomer relation with the attributes customer_numb, first_name, and last_name. Using the syntax for relational algebra, the projection in Figure 2-1 is written: PROJECT customer_rows, first_name, last_name FROM customer GIVING Names_and_numbers 31 Making Vertical Subsets: Project