Teradata Teradata SQL 1

Question 1

Which Teradata SQL clause is used to eliminate duplicate rows from a result set?

Accepted Answer

DISTINCT

Answer

The DISTINCT keyword in a SELECT statement removes duplicate rows from the query result set.

Question 2

What does the QUALIFY clause do in Teradata SQL?

Accepted Answer

Filters rows based on window function results

Answer

QUALIFY filters rows based on the result of an ordered analytical (window) function, similar to HAVING for aggregates.

Question 3

Which Teradata join type returns all rows from both tables, including unmatched rows from each side?

Accepted Answer

FULL OUTER JOIN

Answer

A FULL OUTER JOIN returns all rows from both tables, filling NULLs where there is no match on either side.

Question 4

In Teradata, what is the purpose of the SAMPLE clause?

Accepted Answer

Returns a random subset of rows

Answer

The SAMPLE clause retrieves a random sample of rows from a table, useful for testing or statistical analysis.

Question 5

Which aggregate function in Teradata returns the middle value of an ordered dataset?

Accepted Answer

MEDIAN

Answer

The MEDIAN function returns the middle value of a numeric column when the values are sorted in ascending order.

Teradata Practice Test