Which of the following is not true about the difficulty of index selection?
A) The number of choices of indexes is linear in the number of columns
B) The query optimizer may have subtle reasons not to use an index
C) Values of parameters used in SQL statements of forms often vary from highly selective to not very selective
D) Index choices can be interrelated in a subtle way

Question

Quizplus · Accepted Answer

The number of choices of indexes is not linear in the number of columns, but rather exponential. The number of possible indexes on a table with n columns is 2^n - 1.

Which of the Following Is Not True About the Difficulty