Question

Consider the following relations:

Employee ( E-ID, Name, P-ID)

Project ( P-ID, E-ID, P- Cost, P-Profit)

Consider the following query on these relations:

List the E-ID, Name, P-Code and P-Profit whose E-ID is 2017001

(a) Represent the above query using SQL (1 Marks)

(b) Convert the SQL query into equivalent relational algebraic query (2 Marks)

(c) Draw the query tree for the above relational algebraic query (3 Marks)

(d) Using the query tree, transform the relational algebraic query to

an equivalent relational algebraic query which may reduce the

query evaluation cost.

Answer 1

a. select * from Employee where E-ID = 2017001;