DMC DMC ETL Processes & Data Warehousing

Question 1

What does ETL stand for in data warehousing?

Accepted Answer

Extract, Transform, Load

Answer

ETL stands for Extract, Transform, Load — the three-phase process of pulling data from sources, reshaping it, and loading it into a target system.

Question 2

Which ETL phase is responsible for data cleaning and reformatting?

Accepted Answer

Transform phase

Answer

The Transform phase handles data cleaning, reformatting, deduplication, and applying business rules before loading into the target warehouse.

Question 3

What is a 'staging area' in an ETL process?

Accepted Answer

A temporary storage area where data is held between extraction and loading

Answer

A staging area is temporary storage where extracted data is held and preprocessed before being loaded into the final data warehouse.

Question 4

What is 'incremental loading' in ETL?

Accepted Answer

Loading only new or changed records since the last ETL run

Answer

Incremental loading updates the warehouse by processing only new or modified records since the last run, reducing processing time and resource usage.

Question 5

What is the primary purpose of data profiling in ETL?

Accepted Answer

To analyze the content, quality, and structure of source data

Answer

Data profiling analyzes source data to understand its content, quality, completeness, and structure before designing ETL transformation rules.

DMC - Data Mining Certification Practice Test