Some General Interview Questions for ETL Testing
- 1. How much will you rate yourself in ETL Testing? ...
- 2. What challenges did you face while working on ETL Testing? ...
- 3. What was your role in the last Project related to ETL Testing? ...
- 4. How much experience do you have in ETL Testing? ...
- 5. Have you done any ETL Testing Certification or Training?
- What is the importance of ETL testing? ...
- Explain the process of ETL testing. ...
- Name some tools that are used in ETL. ...
- What are different types of ETL testing? ...
- What are the roles and responsibilities of an ETL tester? ...
- What are the different challenges of ETL testing?
What are things that an ETL tester must know?
Usually, there are a few core skills that an ETL developer needs:
- Understanding of database structure and big data technologies
- Command of reading, analyzing, and transforming data
- Ability to create the best ETL design
- Experience in pulling data from various data source types
- Ability to learn new data tools
- Management and organization skills
- Capability to troubleshoot and manage debugging processes
What are ETL tester responsibilities?
Responsibilities of an ETL tester
- Test ETL software
- Test components of ETL datawarehouse
- Execute backend data-driven test
- Create, design and execute test cases, test plans and test harness
- Identify the problem and provide solutions for potential issues
- Approve requirements and design specifications
- Data transfers and Test flat file
What are the skills required for ETL testing?
- Work in support of the development of company products, tools, platforms and services
- Should have worked in Offshore / Onsite model managing offshore resources
- Providing status metrics on testing
- Strong in ETL data validation developed using Informatica/Abinitio/Datastage/SSIS ETL environments
- Provide demos/walk through regarding testing results
How is a career for ETL testing?
- Write test data scripts, based on ETL mapping artifacts
- Execute data scripts and detailed analysis on the scripts
- Create strategies and test cases for applications that use ETL components
- Data mining and detailed data analysis on data warehousing systems
- Provide input and support big data testing initiative
How do I prepare for ETL testing interview?
The different steps followed in ETL testing process are:Requirement Analyzing. In this step, we understand the business structure and the requirement.Validation and Test Estimation. ... Test Planning and designing the testing environment. ... Test Data Preparation and Execution. ... Summary Report.
What are the 3 layers in ETL?
ETL stands for Extract, Transform, and Load.
How do you explain ETL project in interview?
2) Explain what are the ETL testing operations includes?Verify whether the data is transforming correctly according to business requirements.Verify that the projected data is loaded into the data warehouse without any truncation and data loss.More items...•
What are the types of testing in ETL?
ETL testing fits into four general categories: new system testing (data obtained from varied sources), migration testing (data transferred from source systems to data warehouse), change testing (new data added to data warehouse), and report testing (validate data, make calculations).
What is ETL in SQL?
ETL stands for Extract, Transform and Load. These are three database functions that are combined into one tool to extract data from a database, modify it, and place it into another database.
What is ETL workflow?
An ETL workflow is responsible for the extraction of data from the source systems, their cleaning, transformation, and loading into the target data warehouse. There are existing formal methods to model the schema of source systems or databases such as entity-relationship diagram (ERD).
What are the key steps of the ETL process?
The 5 steps of the ETL process are: extract, clean, transform, load, and analyze. Of the 5, extract, transform, and load are the most important process steps.
Is ETL testing difficult?
Because traditional ETL processes are highly complex and extremely sensitive to change, ETL testing is hard.
Why ETL testing is required?
ETL testing process ensures that the transfer of data from heterogeneous sources to a unified repository occurs as per transformation rules and meets all requirements. The process also helps in the early detection and mitigation of defects and errors.
What are the five stages of ETL testing?
What are the 8 stages of the ETL testing process?Identify your business requirements. ... Assess your data sources. ... Create test cases. ... Begin the ETL process with the extraction. ... Perform the necessary data transformation. ... Load the data into the target destination. ... Document your findings.More items...•
What is ETL testing example?
ETL Source Data Validation Testing The test involves checking for nulls, formats, reference values, duplicates, etc. For example, – Verify that there are no null values in attribute “Name” attribute. – The format of the date in the DOB column should be “YYYY-MM-DD”
Is ETL testing is manual testing?
As mentioned earlier, ETL testing is primarily conducted manually, which makes it a very labor intensive and error prone process. Automating ETL tests allows frequent smoke and regression testing without much user intervention and supports automated testing on older code after each new database build.
How many layers are in the ETL process?
The five layers are data source, ETL (Extract-Transform-Load), data warehouse, end user, and metadata layers. The rest of this section describes each of the layers.
How many layers are in ETL Testing?
A typical ETL tool-based data warehouse uses staging area, data integration, and access layers to perform its functions. It's normally a 3-layer architecture. Staging Layer − The staging layer or staging database is used to store the data extracted from different source data systems.
What are the 3 tiers in data warehousing architecture?
Data Warehouses usually have a three-level (tier) architecture that includes: Bottom Tier (Data Warehouse Server) Middle Tier (OLAP Server) Top Tier (Front end Tools).
Which of the 3 layers is known for handling and storing metadata?
Data Presentation Layer Reporting Tools are used to get Business Data, and Business logic is also applied to gather several kinds of information. Meta Data Information and System operations and performance are also maintained and viewed in this layer.
What is ETL pipeline?
ETL Pipeline refers to a set of processes to extract the data from one system, transform it, and load it into some database or data warehouse. ETL pipelines are built for data warehousing applications, which includes both enterprise data warehouse as well as subject-specific data marts. ETL pipelines are also used for data migration solutions. Data warehouse/ business intelligence engineers build ETL pipelines.
What is ETL in data warehouse?
ETL stands for Extraction, Transformation, and Loading. It is an essential concept in Data Warehousing systems. There are three basics steps in Data Integration Process. Extraction stands for extracting the data from different data sources such as transactional systems or applications. Transformation stands to apply the conversion rules on data so that it becomes suitable for analytical reporting. Loading process involves, to move the data into the target system, i.e., Data Warehouse.
What is ETL tool?
ETL tools are generally used in Data Migration Project. If any organization is managing the data in Oracle 10g previously, now the organization wants to use SQL server cloud database, then there is a need to move the data from source to target. For this kind of movement, ETL tools are very useful. If we want to write the code for ETL, it is a very time-consuming process. To make this simple, we use ETL tool, which makes the coding simple PL SQL or T- SQL code. So the ETL process is useful in Data Migration Projects.
What is data extraction?
Data Extraction is nothing, but it is extracting the data from multiple different sources using ETL tools.
What is an ETL mapping sheet?
ETL mapping sheet contains all the necessary information from the source file and stores the details in rows and column. Mapping sheets help in writing the SQL queries to speed up the testing process.
Why is staging important?
In the staging, area data is cleansed and checked for any duplication. The staging area is designed to provide many benefits, but the primary goal is to use the staging area. It is used to increase efficiency, ensure the data integrity, and support the data quality operations.
What is manual testing?
Manual testing focuses on the functionality of the program while the ETL testing is related to database and its count.
What is the difference between ETL and database testing?
Answer:#N#The difference between ETL testing and database testing is as below: 1 ETL testing usually focuses on business intelligence reporting while database testing involves an integration of data. 2 The tools that are used for ETL testing are Cognos, QuerySurge, and Informatica while QTP and selenium are used for automation of database testing. 3 The analysis of data in ETL has a potential impact on data. The normal database testing has architectural implementation impacts 4 ETL testing has deformalized data while database testing uses normalized data.
What tools are used for ETL testing?
The tools that are used for ETL testing are Cognos, QuerySurge, and Informatica while QTP and selenium are used for automation of database testing.
What is partitioning in Informatica?
Answer:#N#In order to improve performance, the transactions present are subdivided and this process is known as partitioning. Partitioning helps Informatica Server to create different connections to its various sources. The types of partitions are:#N#Round Robin Partitioning: All data is evenly distributed among all partitions. In all these partitions when the number of rows is approximately the same then this partitioning is used.#N#Hash Partitioning: In this partitioning , all partitioning keys are grouped among the partitions apply a hash function. It is used to ensure the processed group of rows with the same partitioning key have the same partitions.
What is ETL testing?
ETL testing must have a well-defined strategy which makes this entire process easier. The process includes analyzing the requirement, Validation and Test Estimation, Test Planning and Designing the testing environment, Test Data preparation and Execution and creating a Summary Report.
What is a surrogate key?
Answer: A surrogate key can be said as a unique identifier which can be used for modeling an entity or an object. It can be a unique key whose significance is to be a primary identifier of any object or entity which is not derived from any other database and cannot be used as a primary key.
What is source data extraction?
Source data extraction and data transformation where data is restructured as per customer requirements. Data transformation includes the process of data cleansing and value transformations. It also involves the process of surrogate key assignments.
What is data purging?
Answer:#N#Deleting a piece of data from the data warehouse is known as data purging . This data which is deleted is usually data which has rows with null values or spaces which need clean up. In this process cleaning of this kind of garbage or junk, values are done.
What is the advantage of using a datareader?
The advantage of using the DataReader Destination Adapter is that it populates an ADO recordset (consist of records and columns) in memory and exposes the data from the DataFlow task by implementing the DataReader interface, so that other application can consume the data.
What is partitioning in Informatica?
To improve performance, transactions are sub divided, this is called as Partitioning. Partioning enables Informatica Server for creating of multiple connection to various sources
What is ETL in data warehousing?
1) What is ETL? In data warehousing architecture, ETL is an important component, which manages the data for any business process. ETL stands for Extract, Transform and Load. Extract does the process of reading data from a database.
How is Informatica data distributed?
By informatica data is distributed evenly among all partitions
What to do if you have non-OLEBD source?
In case if you have non-OLEBD source for the lookup then you have to use Cache to load data and use it as source
What is the difference between data mining and data warehousing?
Data mining can be define as the process of extracting hidden predictive information from large databases and interpret the data while data warehousing may make use of a data mine for analytical processing of the data in a faster way. Data warehousing is the process of aggregating data from multiple sources into one common repository.
What is the numeric data based on columns in a fact table called?
The numeric data based on columns in a fact table is known as Measures
