Lecture Notes for

, An, project R on subset of columns T := R[Ai1, . . ., Aik], where list in brackets is a subset of the complete set of attributes. Cross out all columns and column values in R not in set, then eliminate duplicate rows. (See Def 2.7.1 in text.) Example 2.7.1. List all customer names from the CUSTOMERS table of Figure 2.2. ................
................