Data Warehousing on AWS Training Data Lake Integration 1

Question 1

What AWS service allows Amazon Redshift to query data directly in Amazon S3 without loading it into Redshift?

Accepted Answer

Redshift Spectrum

Answer

Redshift Spectrum extends Redshift's SQL capabilities to query data stored in S3 using external tables, without requiring data to be loaded into Redshift.

Question 2

When using Redshift Spectrum, where are external table definitions stored?

Accepted Answer

AWS Glue Data Catalog or Amazon Athena metastore

Answer

Redshift Spectrum uses the AWS Glue Data Catalog or the Amazon Athena metastore as the external metadata repository to define schemas for external tables.

Question 3

Which file format is NOT natively supported for querying with Redshift Spectrum?

Accepted Answer

Microsoft Excel (.xlsx)

Answer

Redshift Spectrum supports open formats such as Parquet, ORC, JSON, CSV, and Avro, but does not support proprietary binary formats like Excel.

Question 4

What is the primary performance advantage of using columnar file formats like Parquet with Redshift Spectrum?

Accepted Answer

They reduce the amount of data scanned, lowering costs and improving query speed

Answer

Columnar formats like Parquet allow Spectrum to read only the columns referenced in a query, drastically reducing the data scanned and the per-byte query cost.

Question 5

In Redshift Spectrum, external tables referencing S3 data must be created inside which type of schema?

Accepted Answer

External schema

Answer

Redshift Spectrum external tables must reside in an external schema that is mapped to the AWS Glue Data Catalog or Athena, signaling that data lives outside Redshift.

Data Warehousing on AWS Training Practice Test

Data Warehousing on AWS Training Practice Test

Data Warehousing on AWS Training Data Lake Integration 1