Question

for a table T, the characteristics of three of its columns are given below.
. column A has unique values
. column B has a wide range of values
. column C many nulls and the non-null values are not searched much
which of these column/s is/are good for indexing?

(a) A
(b) C
(c) None
(d) B

Answer 1

A column characteristics will be good.