1Z0-071 Aggregating Data with Group Functions 1

Question 1

Which GROUP BY function returns the total sum of a numeric column?

Accepted Answer

SUM()

Answer

COUNT()

Answer

AVG()

Answer

MAX()

Question 2

What happens to NULL values when using the AVG() function in Oracle SQL?

Accepted Answer

They are ignored entirely

Answer

They are counted as zero

Answer

They cause an error

Answer

They are replaced with 1

Question 3

Which clause is used to filter the results of a GROUP BY query?

Accepted Answer

HAVING

Answer

WHERE

Answer

FILTER

Answer

LIMIT

Question 4

What does the COUNT(*) function return?

Accepted Answer

Total number of rows including NULLs

Answer

Number of non-NULL values in a column

Answer

Sum of all rows

Answer

Number of distinct values

Question 5

Which statement about the GROUP BY clause is TRUE?

Accepted Answer

Columns in SELECT not in an aggregate must appear in GROUP BY

Answer

GROUP BY must always be followed by HAVING

Answer

NULL values cannot appear in a GROUP BY column

Answer

GROUP BY eliminates duplicate rows without aggregation

Question 6

Which function returns the highest value in a set of values?

Accepted Answer

MAX()

Answer

UPPER()

Answer

GREATEST()

Answer

TOP()