Teradata For Beginner 4

Question 1

In Teradata, what is a Secondary Index (SI) used for?

Accepted Answer

To provide an alternative access path to rows without changing data distribution

Answer

A Secondary Index creates a subtable that provides an alternative lookup path without changing where the actual rows are stored.

Question 2

Which Teradata command collects statistical data about table columns to help the optimizer?

Accepted Answer

COLLECT STATISTICS

Answer

COLLECT STATISTICS gathers demographic data about column values and stores it so the query optimizer can build better execution plans.

Question 3

What is the BYNET in Teradata architecture?

Accepted Answer

The high-speed interconnect network between nodes that carries all inter-AMP communication

Answer

BYNET is Teradata's proprietary high-bandwidth, fault-tolerant interconnect that enables fast communication and data transfer between all nodes.

Question 4

Which of the following best describes a Unique Primary Index (UPI) in Teradata?

Accepted Answer

It guarantees uniqueness and routes each row to exactly one AMP

Answer

A UPI enforces uniqueness on the indexed column(s) and ensures each unique value hashes to a single, specific AMP.

Question 5

What does the COALESCE function do in Teradata SQL?

Accepted Answer

Returns the first non-NULL value from a list of expressions

Answer

COALESCE evaluates its arguments in order and returns the first expression that is not NULL.

Teradata Practice Test