Exam 1z0-082 topic 1 question 72 discussion

D is correct

The only statement that is true about aggregate functions is: D. The MAX and MIN functions can be used on columns with character data types The other statements are false: A. Aggregate functions can be nested to any number of levels - Aggregate functions can be nested to a maximum depth of 15 levels. B. The AVG function implicitly converts NULLS to zero - The AVG function ignores NULLS when calculating the average. C. Aggregate functions can be used in any clause of a SELECT statement - Aggregate functions can only be used in the SELECT clause and the GROUP BY clause of a SELECT statement. Aggregate functions are functions that perform calculations on groups of rows. Some common aggregate functions include COUNT(), SUM(), AVG(), MAX(), and MIN(). Aggregate functions can be used to calculate a variety of statistics, such as the total number of rows in a table, the average value of a column, or the highest value in a column.

The correct answer is D It is true that MAX and MIN can be used with character data types. B is incorrect because AVG ignores NULL values C is incorrect because aggregate functions cannot be used in any clause of the select. That is, they are used with SELECT statements that select many rows, scan a set of rows, and return a single response for all of them.

d is correct

A is wrong. Aggregates are not allowed on an outer query. D is correct MAX is allowed only on expressions that evaluate to built-in data types (including CHAR, VARCHAR, DATE, TIME, CHAR FOR BIT DATA, etc.). https://docs.oracle.com/javadb/10.6.2.1/ref/rrefsqlj27781.html#:~:text=MAX%20is%20an%20aggregate%20function,BIT%20DATA%2C%20etc.). https://docs.oracle.com/javadb/10.6.2.1/ref/rrefsqlj33923.html#rrefsqlj33923

D is correct. Max level aggregate functions is 2.

A is wrong. I think the correct is D