CDP Data Warehousing and Business Intelligence 3

Question 1

What is the primary advantage of columnar storage over row-based storage for analytical queries?

Accepted Answer

Improved compression and faster reading of specific columns without scanning entire rows

Answer

Columnar storage stores data by column rather than row, enabling better compression of similar values and faster reads for analytics that access only specific columns.

Question 2

In BI, what is 'self-service analytics'?

Accepted Answer

Enabling business users to create their own reports and analyses without requiring IT intervention

Answer

Self-service analytics empowers business users to independently access, analyze, and visualize data without needing to submit requests to IT or data teams.

Question 3

What is 'data freshness' in a data warehouse context?

Accepted Answer

How current or up-to-date the data in the warehouse is relative to the source systems

Answer

Data freshness measures how current the warehouse data is compared to source systems, reflecting the lag introduced by batch load frequencies.

Question 4

What is a 'junk dimension' in dimensional modeling?

Accepted Answer

A single dimension table that consolidates miscellaneous, low-cardinality flag and indicator fields from the fact table

Answer

A junk dimension consolidates miscellaneous boolean flags and low-cardinality indicators into a single dimension table to reduce fact table width.

Question 5

What does 'slice and dice' mean in OLAP analysis?

Accepted Answer

Filtering data by selecting specific values on dimensions (slice) and viewing data across multiple dimensions simultaneously (dice)

Answer

Slicing selects a subset of data by fixing one dimension's value, while dicing selects specific values across multiple dimensions to create a smaller subcube for analysis.

CDP - Certified Data Professional Practice Test

CDP - Certified Data Professional Practice Test

CDP Data Warehousing and Business Intelligence 3