Free ETL Testing Basic Questions and Answers — Questions and Answers
Question 1: ___ automates ETL testing and management to make sure the data don't affect production systems.
- Irrelevant Data Validation
- Irrelevant Duration Validation
- Informatica Data Validation (Correct answer)
- Informatica Duration Validation
Correct answer: Informatica Data Validation
'Informatica Data Validation' is a specific tool or suite offered by Informatica, a leading data integration vendor, designed to automate ETL testing and data quality management. It helps ensure that data moving through ETL pipelines is accurate, complete, and consistent, thereby preventing data quality issues from affecting production systems. This automation streamlines the testing process and improves data reliability.
Question 2: Testing the changed data values against the expected data values is called ___ testing.
- Metadata
- Data Transformation
- Source to target (Correct answer)
- Data Accuracy
Correct answer: Source to target
'Source to target' testing, also known as data transformation testing, involves comparing the transformed data values in the target system against the expected data values based on the source data and defined transformation rules. This type of testing verifies that all business logic and transformations applied during the ETL process have been executed accurately. It ensures data integrity and correctness after the transformation phase.
Question 3: Data types, data lengths, indexes, and constraints are all measured as part of __ testing.
- Data Transformation
- Data Quality
- Metadata (Correct answer)
- Data Accuracy
Correct answer: Metadata
'Metadata testing' focuses on validating the structural information about the data, rather than the data values themselves. This includes checking data types, data lengths, indexes, constraints, and other schema-related attributes in both source and target systems. Ensuring metadata consistency is crucial for the proper functioning of the data warehouse and downstream applications.
Question 4: Difficult data will be reported by __ tests if there are invalid characters, invalid character patterns, or wrong upper- or lowercase case.
- Transformation
- Syntax (Correct answer)
- Reference
- Accuracy
Correct answer: Syntax
'Syntax' tests are designed to identify data that does not conform to predefined patterns or rules for its format. These tests will report difficult data if it contains invalid characters, incorrect character patterns, or improper casing (e.g., wrong upper- or lowercase). Syntax testing ensures that data adheres to expected structural formats, which is crucial for data quality and usability.
Question 5: When new data is introduced to existing data, a data integrity test is performed for ___ testing.
- Report
- Migration
- Incremental ETL (Correct answer)
- GUI/Navigation
Correct answer: Incremental ETL
'Incremental ETL' testing is performed when new data is added to an existing data warehouse or target system. This type of testing focuses on ensuring that only the new or changed data is correctly extracted, transformed, and loaded without corrupting or duplicating existing data. It's essential for maintaining data integrity and efficiency in ongoing data loading processes.
Question 6: A ___ compares data between two systems, one source and one target, without changing the data in either system.
- Value Compression
- Value Contraction
- Value Comparison (Correct answer)
- Value Compromise
Correct answer: Value Comparison
A 'Value Comparison' tool or process is used to directly compare data between two systems, typically a source and a target, without altering the data in either system. This comparison helps identify discrepancies and ensures that data has been accurately transferred or transformed. It's a fundamental technique in ETL testing to verify data integrity.
Question 7: For both the source and destination tables, a ___ holds all the columns and their lookups in reference tables.
- DB Schema of Source
- DB Schema of Target
- Mapping Sheet (Correct answer)
- None of the above
Correct answer: Mapping Sheet
A 'Mapping Sheet' (or ETL mapping document) is a crucial document in ETL projects that details how data elements from source tables map to columns in target tables. It includes information about data types, lengths, transformation rules, and lookups in reference tables for both source and destination. This sheet serves as a blueprint for developers and testers, ensuring consistent data flow and transformation.
Question 8: QualiDI's ___ testing platform provides ETL and end-to-end testing.
- Automated (Correct answer)
- Non-automated
- Semi-automated
- None of the above
Correct answer: Automated
QualiDI is a known data quality and testing platform that offers 'Automated' testing capabilities for ETL and end-to-end data pipelines. Automation in ETL testing significantly reduces manual effort, speeds up the testing cycle, and improves the accuracy and consistency of test results. This allows for more frequent and comprehensive validation of data quality.
Question 9: A data migration pipeline consists of ___ data from an input source being transformed and loaded into an output destination for analysis, reporting, and synchronization (such as a datamart, database, and data warehouse).
- Modifying
- Adding
- Deleting
- Extracting (Correct answer)
Correct answer: Extracting
A data migration pipeline begins with 'Extracting' data from an input source. This is the initial step where raw data is pulled from various operational systems or databases. Once extracted, the data then undergoes transformation and is subsequently loaded into the output destination for analysis, reporting, or synchronization purposes.
Question 10: Which of these tasks is NOT part of the ETL Transformation Process?
- Cleaning
- Filtering
- Addressing (Correct answer)
- Joining
Correct answer: Addressing
The ETL Transformation Process involves various tasks like cleaning, filtering, joining, aggregating, and deriving new values from the extracted data. 'Addressing' is not a standard task or term directly associated with the core data manipulation functions within the ETL transformation phase. The other options (Cleaning, Filtering, Joining) are all common and essential transformation steps.
Question 11: Data processing modules made up of fact tables and dimensions from the data warehouse are called _____.
- Cubes (Correct answer)
- OLAP
- OLTP
- None of the above
Correct answer: Cubes
'Cubes' are multidimensional data structures used in Online Analytical Processing (OLAP) systems, which are often built on top of data warehouses. They are made up of fact tables and dimensions, allowing for fast analysis of data across various business dimensions. Cubes pre-aggregate data, making complex queries and reporting highly efficient.
Free ETL Testing Basic Questions and Answers
___ automates ETL testing and management to make sure the data don't affect production systems.