Data Processing ETL and Data Transformation 1 — Questions and Answers
Question 1: What does ETL stand for in data processing?
- Extract, Transform, Load (Correct answer)
- Export, Transfer, Log
- Evaluate, Test, Launch
- Encode, Transmit, Link
Correct answer: Extract, Transform, Load
ETL stands for Extract, Transform, Load — the three-phase process of pulling data from sources, converting it, and loading it into a target system.
Question 2: What happens during the 'Extract' phase of an ETL process?
- Data is pulled from one or more source systems (Correct answer)
- Data is cleaned and converted to a target format
- Data is written into the destination database
- Data is compressed and archived
Correct answer: Data is pulled from one or more source systems
The Extract phase retrieves raw data from source systems such as databases, flat files, or APIs for further processing.
Question 3: What is data mapping in an ETL pipeline?
- Defining how source fields correspond to destination fields (Correct answer)
- Creating geographic visualizations from address data
- Encrypting data before transport
- Sorting data by geographic region
Correct answer: Defining how source fields correspond to destination fields
Data mapping defines the relationship between each source data element and its corresponding target field in the destination system.
Question 4: What is the purpose of a staging area in ETL processing?
- A temporary storage location where data is held between extraction and loading (Correct answer)
- The final destination for processed data
- A backup of the production database
- A tool for visualizing ETL pipeline performance
Correct answer: A temporary storage location where data is held between extraction and loading
A staging area is an intermediate storage zone where extracted data is held and transformed before being loaded into the target data warehouse.
Question 5: Which transformation converts data from one format to another, such as date formats?
- Data conversion (Correct answer)
- Data masking
- Data partitioning
- Data archiving
Correct answer: Data conversion
Data conversion transforms values from one format to another, such as changing date representations or unit measurements to match target system requirements.
Question 6: What is incremental loading in ETL?
- Loading only new or changed records since the last ETL run (Correct answer)
- Loading one record at a time in sequence
- Loading data in alphabetical order
- Loading all data from scratch every time
Correct answer: Loading only new or changed records since the last ETL run
Incremental loading processes and loads only the records that have been added or modified since the last ETL execution, improving efficiency.
Data Processing ETL and Data Transformation 1
What does ETL stand for in data processing?