Teradata Teradata SQL 2

Question 1

Which Teradata SQL command is used to remove all rows from a table without logging individual row deletions?

Accepted Answer

DELETE ALL

Answer

DELETE ALL (or DELETE tablename ALL) removes all rows quickly; Teradata also supports TRUNCATE TABLE for similar fast deletion.

Question 2

What is the purpose of the WITH clause (Common Table Expression) in Teradata SQL?

Accepted Answer

Defines a temporary named result set for use within the query

Answer

The WITH clause defines a Common Table Expression (CTE), which is a temporary named result set referenced within the same query.

Question 3

Which string function in Teradata returns the position of a substring within a string?

Accepted Answer

INDEX

Answer

The INDEX function in Teradata returns the position of the first occurrence of a substring within a string.

Question 4

What does COALESCE return in Teradata SQL?

Accepted Answer

The first non-NULL value from a list of expressions

Answer

COALESCE evaluates each expression in order and returns the first non-NULL value found in the list.

Question 5

In Teradata, which keyword is used to sort query results in descending order?

Accepted Answer

DESC

Answer

The DESC keyword in an ORDER BY clause sorts the result set from the highest to the lowest value.

Teradata Practice Test