1.
Which of the following tasks are handled by a DBMS?
a. Ensure that a user’s access to the database is restricted to the appropriate subschema.
b. Translate commands stated in terms of the database model into actions compatible with the actual data storage system.
c. Disguise the fact that the data in the database is actually scattered among many computers in a network.
2.
Describe how the following information about
railways, trains (for a particular day), and passengers
would be represented in a relational
database:
Trains: Rolar, Omni, and Holiday
Trains for Rolar: R221, R567, and R234
Holiday special Trains: H897 and H008
Trains for Omni: O999 and O815
John has reservations on R221 (seat 34U),
R567 (seat 23U), and R234 (seat 43L).
Henry has reservations on O999 (seat 15L)
and H008 (seat 18L).
Duke has reservations on H897 (seat 7U) and
O815 (seat 2L).