CIS395 - BMCC - Spring 2018 02/07/2018

Homework 01: The Relational Mode

Submission Deadline: Wednesday 02/14/2018 11:00 AM.

True False -- A tuple is a named column of a relation.

True False -- Each attribute in a relation has a distinct name.

True False -- The degree of a relation is the number of attributes it contains.

True False -- The degree of a relation is a property of the intension of the relation.

True False -- The cardinality of a relation is a property of the intension of the relation.

True False -- A domain is the set of allowable values for one or more attributes.

True False -- A foreign key is the candidate key that is selected to identify tuples.

8.

The following tables form part of a database held in a relational DBMS:

Hotel (hotelNo, hotelName, city)

Room (roomNo, hotelNo, type, price)

Guest (guestNo, guestName, guestAddress, guestEmail)

Booking (guestNo, hotelNo, roomNo, dateFrom, dateTo)

Assumption: A hotel name cannot be repeated in the same city. Identify, for each table, the followings:

Foreign keys Candidate keys

Primary keys

Alternate keys