21.What is the technique known as destructive update?

Select one:

a. Not having off-site backup procedures

b. Replacing an old data value with a new value

c. Deleting digital audit trails

d. Destructing physical database files to prevent update

22.Many-to-many relationships cannot be represented by which database model?

Select one:

a. The relational model

b. The DDP model

c. The hierarchical model

d. The network model

23.What kind of control is used when the level of precision used in a calculation is greater than that is used for reporting?

Select one:

a. Sign check

b. Range check

c. Rounding error routines

d. Validity control

24.A company has decided that paychecks are not to be distributed to employees by their direct supervisors. Instead, a paymaster should do this. What kind of control is this?

Select one:

a. Supervision

b. Reconciliation

c. Authorization

d. Segregation of duties