Data Processing ETL and Data Transformation 2

Question 1

What is data aggregation in ETL transformation?

Accepted Answer

Combining multiple values into a single summary value such as a sum or average

Answer

Splitting one large table into multiple smaller ones

Answer

Encrypting data before it is loaded

Answer

Filtering out invalid records before storage

Question 2

What is a data pipeline?

Accepted Answer

A series of automated steps that move and transform data from source to destination

Answer

A physical cable connecting two database servers

Answer

A type of database index for large tables

Answer

A graphical report of data flow between departments

Question 3

What does data enrichment mean in the context of ETL?

Accepted Answer

Enhancing source data by adding additional information from other sources

Answer

Removing unnecessary columns before loading

Answer

Compressing data to reduce storage costs

Answer

Sorting records before inserting them into tables

Question 4

Which tool is widely used in the US enterprise environment for building ETL workflows visually?

Accepted Answer

Apache Informatica PowerCenter

Answer

Microsoft Notepad

Answer

Adobe Acrobat

Answer

VirtualBox

Question 5

What is a slowly changing dimension (SCD) in data warehousing?

Accepted Answer

A dimension table whose attribute values change slowly over time

Answer

A table that is rarely queried

Answer

A dimension with only one row of data

Answer

A compressed archive of historical fact tables

Question 6

What is the difference between ETL and ELT?

Accepted Answer

ETL transforms data before loading; ELT loads raw data first then transforms it in the target system

Answer

ETL is for small datasets; ELT is for large datasets only

Answer

ETL uses SQL only; ELT uses Python only

Answer

ETL is batch-only; ELT is always real-time