Question 9 Which lock allow many transactions to use the same variable

a. None

b. s-lock

c. x-lock

Question 10 If the speed of a disk is 10 Mbs, the time to read 100 Gb is

a. 10* (2 to power 20)

b. 10* (2 to power 10)

c. 100* (2 to power 20)

d. None is correct

Question 11 The search key in the secondary index is the same field used to sort the table.

a. False

b. True

Question 12 Which of the following is not correct

a. spatial databases stores shapes in 2D and 3D

b. Overflow is an example of a global failure

c. Bitmap index is used with multi-condition and all of them having equal sign.

d. All are correct

Question 13 Which of the following is not correct

a. Sensors are an important source of big data

b. Starvation is one of the locks problems

c. Views are used to avoid illegal access of data

d. All are correct

Question 14 Index values must be sorted.

a. True

b. False

Question 15 The table can have many indexes at the same time

a. False

b. True

Question 16 Which of the following is not correct

a. XML is a semi - structured data

b. Uncompleted transactions must be undone after failure because of Atomic

c. RAM is faster than sequential access memory

d. All are correct