41. In SQL, which command is used to select only one copy of each set of duplicable rows
A. SELECT DISTINCT
B. SELECT UNIQUE
C. SELECT DIFFERENT
D. All of the above
E. None of the above
42. The physical location of a record is determined by a mathematical formula that transforms a file key into a record location in
A. a tree file
B. an indexed file
C. a hashed file
D. a sequential file
E. None of the above
43. Which command is used to select distinct subject (SUB) from the table (BOOK)?
A. SELECT ALL FROM BOOK
B. SELECT DISTINCT SUB FROM BOOK
C. SELECT SUB FROM BOOK
D. All of the above
E. None of the above
44. The master list of an indexed file
A. is sorted in ascending order
B. contains only a list of keys and record numbers
C. has a number assigned to each record
D. both (b) and (c)
E. None of the above
45. Which of the following is not the responsibility of the utilities component of DBMS software?
A. creating the physical and logical designs
B. removing flagged records for deletion
C. creating and maintaining the data dictionary
D. monitoring performance
E. None of the above