For which one would you use an index fast full scan to improve performance?
A. a query having all the columns of an index in the where clause
B. a query that does not need to access table rows
C. a query that needs to access table rows along with an index
D. a column in an index that is compressed
All of the columns required by SQL must reside in the index tree; that is, all columns in the SELECT and
WHERE clauses must exist in the index.