One measure that determines the need for an index is the ____ of the column you want to index.____ refers to the number of different values a column could possibly have.
A) Database statistics
B) Data sparsity
C) Primary keys
D) Query optimization

Question

Quizplus · Accepted Answer

Data sparsity determines the need for an index as it refers to the number of different values a column could possibly have. If a column has high data sparsity (i.e. there are only a few distinct values in the column), then creating an index on that column would improve query performance. However, if a column has low data sparsity (i.e. there are many distinct values in the column), then creating an index on that column would not necessarily improve query performance and could even slow down inserts and updates to the table.

One Measure That Determines the Need for an Index Is