Data Warehousing on AWS Training Performance Optimization

Question 1

Which Amazon Redshift feature automatically sorts and distributes data to optimize query performance?

Accepted Answer

Automatic Table Optimization (ATO)

Answer

Manual VACUUM

Answer

COPY command

Answer

UNLOAD command

Question 2

What is the purpose of the VACUUM command in Amazon Redshift?

Accepted Answer

Reclaim storage and resort rows

Answer

Delete unused columns

Answer

Compress data blocks

Answer

Rebuild indexes

Question 3

Which distribution style should you choose for a large fact table that is frequently joined with dimension tables?

Accepted Answer

KEY

Answer

ALL

Answer

EVEN

Answer

AUTO

Question 4

What does the ANALYZE command do in Amazon Redshift?

Accepted Answer

Updates table statistics for the query planner

Answer

Compresses columnar data

Answer

Sorts table rows

Answer

Encrypts table data

Question 5

Which Redshift feature allows you to cache the results of repeated queries in memory?

Accepted Answer

Result Caching

Answer

Materialized Views

Answer

Workload Manager

Answer

Spectrum Cache

Question 6

What is a sort key in Amazon Redshift and why is it important for performance?

Accepted Answer

A column used to physically order data on disk for faster range scans

Answer

A primary key that enforces uniqueness

Answer

An index created on frequently queried columns

Answer

A partition key that distributes data across nodes