Encryption-Based Multilevel Model for DBMS - Multilevel Security for Relational Databases - page 103

models and the encryption-based multilevel database model when
executing the selection query.
The SELECT statement that is used in the following experiments
is described as follows:

Select * from Employee where department = 'Sales.'

5.4.2.1 Impact of Varying the Number of Tuples This experiment is used
to measure the impact of changing the number of tuples on the
performance of the multilevel relational database models. The num-
ber of tuples is varied to 100,000, 500,000, 1,000,000, 1,500,000
and 2,000,000. Fix the number of attributes at three; fix the
number of security levels at four. From Figure 5.8 the response
times grow for all models as the number of tuples is increased.

50

Number of attributes = 3
Number of security levels = 4

45

40

35

30

25

20

15

10

5

0

0 0.5 1

Number of Tu ples

1.5 2

Millions

SeaView
MLR

Jajodia-Sandhu
Belief-Consistent

Smith-Winslett
MLS-Encryption

Figure 5.8 Impact of changing the number of tuples in the selection query. (M. Garuba. 2003.
PhD thesis, Department of Mathematics, Royal Holloway, University of London, Egham, Surrey.
Available at http://digirep.rhul.ac.uk/items/f076f347-2036-6bd0-98c8-e1d2dc9cf4ab/1/, accessed
April 2011.)