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

Faster inserts and updates for transactional workloads

Answer

Simpler query syntax for developers

Answer

Better support for ACID transactions

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

Automated report generation without any human involvement

Answer

A BI tool that monitors itself for errors

Answer

Analytics performed on customer self-service data

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

Whether data has been recently archived

Answer

The percentage of non-null values in a dataset

Answer

The number of new records added in the last load

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 dimension containing low-quality data pending cleansing

Answer

An unused dimension that should be deleted

Answer

A dimension storing deleted historical records

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

Splitting large tables into smaller partitions

Answer

Deleting rows and columns from a report

Answer

Normalizing data before loading into an OLAP cube

Question 6

What is the 'bus matrix' (also called the data warehouse bus matrix) used for?

Accepted Answer

A planning tool that maps which business processes (fact tables) share which conformed dimensions

Answer

Documenting server infrastructure for the data warehouse

Answer

A performance benchmarking tool for ETL jobs

Answer

A matrix of user access permissions for data mart tables