In my previous articles i have explained about etl definition and its concept in brief. This article basically gives you sql interview questions for testers so that tester will not face any. Etl interview questions and answers etl interview tips. Etl testing a interview questions etl stands for extract, transform, and load. Etl mapping sheets provide a significant help while writing queries for data verification. Writing sql queries for various scenarios like count test should be able to carry our different types of tests such as primary key, defaults and keep a check on the other functionality of the etl process. Select empno, count from emp group by empno having count 1. Etl 102 etl interview questions and 406 answers by expert members with experience in etl subject. I found so many comments from different users about sql interview questions for testers. An etl testers need to be comfortable with sql queries as etl testing may involve writing big queries with multiple joins to validate data at any stage of etl. We can use the employeedetails table to fetch the employee details with a where clause for the managerselect empid, fullname from employeedetails where managerid 986. Sql structured query language and purpose is in order to store or manage the information with relational database sql is a set of standards maintain by the anscii group installation procedures for oracle 10g,11g. Etl testing interview questions and answers etl testing.
Click here installation of oracle 11g in windows 7. However, you can override the sql in the source qualifier to join with the lookup table to perform. Etl testing interview questions and answers sql, ibm. It is an important concept in data warehousing systems. Here is an awesome 238 sql queries list download instantly at free of cost. Reconciliation checkselect countfrom source tablewhere list of conditionsselect countfrom target tablewhere list of conditionsexpected output. These are the most common and useful sql interview questions for freshers as well as experienced candidates. In etl testing you need to compare source to target data comparison.
Write an sql query to fetch the empid and fullname of all the employees working under manager with id 986. The knowledge of sql is a must for any tester and this article will help you in preparing the interview. Structured query language sql is a database tool that is used to. Video talks about sql query interview questions sql interview questions sql interview questions and answers top sql questions sql real time scenario based in. Etl testing is very much dependent on the availability of test data with. Etl testing interview questions and answers advanced sql.
A free inside look at etl testing interview questions and process details for 14 companies all posted anonymously by interview candidates. Manual testing is highly timeconsuming where you need technical knowledge to write the test cases and the scripts. This sheet helps the experts in writing the sql queries for the etl tools testing. Tailor your resume by picking relevant responsibilities from the examples below and then add your accomplishments. Mar, 2017 in this etl testing tutorial for beginners, learn what is etl testing in software testing and basics of data migration.
Etl testing is normally performed on data in a data warehouse system, whereas database testing is commonly performed on transactional systems where the data comes from different applications into the transactional database. Basics to advanced concepts of sql are covered in this article. Open source intelligence tools manual testing tutorial what is sharepoint information. Discuss each question in detail for better understanding and indepth knowledge of etl. Extraction stands for extracting data from different data sources such as transactional systems or applications. Having a welldefined etl testing strategy can make the testing process much easier. Here, the company will get to know if they are in the right path on the selection of the tool. Learn about the data migration testing approach, what to put in data.
Refer to these questions for a quick revision of major sql concepts before appearing for an interview. Thanks for sharing such a nice questions i usually visit your website for interview. Excellent information regarding etl testing interview questions. The data that needs to be tested is in heterogeneous data sources eg. In this article i would like to explain the etl testing interview questions with answers in detail. Apr 16, 2020 when an etl tool has been selected, the next logical step would be testing using these tools. Top etl testing interview questions and answers for 2020. Sql interview questions for testers advanced sql queries. The data from these oltp are structured and optimized for querying and data analysis in a data warehouse. Structured query language and purpose is in order to store or manage the information with relational database. Etl transformation is carried out using multiple sql queries as the process is not simple. In this etl testing process, a group of experts comprising the programming and developing team will start writing sql. The tester requires a sql knowledge to test application in a proper way.
In this etl testing tutorial for beginners, learn what is etl testing in software testing and basics of data migration. These are the most common and useful sql interview questions for. Apr 16, 2020 90 most popular sql interview questions and answers. It has a set of top 65 questions which an interviewer plans to ask during an interview process. Our sql interview questions blog is the onestop resource from where you can boost your interview preparation. Sql is a set of standards maintain by the anscii group. Hence, this process need to be followed before you start the data integration processed with the selected etl tool. Etl testing sql queries together for each row and verify the transformation rules. The best etl testing interview questions updated 2020. Jan 06, 2018 video talks about sql query interview questions sql interview questions sql interview questions and answers top sql questions sql real time scenario based in. A data mart is a subset of a data warehouse that can provide data for reporting. This type of testing is performed to check the data integrity when new data is added to the existing data. Structured query language sql is a database tool that is used to create and access the database to support software applications.
This part contains only etl interview questions and answers for both freshers as well as experienced pdf. These sample questions are framed by experts from intellipaat who train for etl testing training to give you an idea of the type of questions asked in interviews. In contrast, a bi tool is used to generate interactive and adhoc reports for endusers, dashboard for senior management, data visualizations for monthly, quarterly, and annual board meetings. Etl testing involves comparing of large volumes of data typically millions of records. The table is a collection of record and its information at a single view. Set operators, difference between union and union all, delete,drop and truncate. Operators are used to specify conditions in an sql statement and to serve as. The difference between manual testing and etl testing is. Etl interview questions and answers etl interview questions. Transformation stands for applying the conversion rules on data so that it becomes suitable for analytical reporting. Source count target countin the above check, there are two queries, one fetching the count of total numberof records in source table and the other.
A list of frequently asked etl testing interview questions and answers are given below. And target table query will be2 select count from sourcetable a, targettable b where a. So sample queries on source data is 1 select count from sourcetable where id is not null. It should be kept handy to verify any detail in mapping sheets. We have taken full care to give the best answers to all the questions. The loading process involves moving the data into the target. Base queries need to be make and testing the product. Database migration testing etl testing with interview. Data is often transformed which might require complex sql queries for comparing the data. Apr 22, 20 in etl testing you need to compare source to target data comparison. So we need this information currently i am looking for etl testing jobs in hyderabad location. Thanks for sharing such a nice questions i usually visit your website for interview questions etl testing. Apart from the below questions, you can download more 53 sql interview questions document from here click here to download. Starting at the root, walk from the top down, and eliminate employee higgins in the result, but.
Hence, this process needs to be completed before you start the data integration with the selected etl tool. Thanks for sharing such a nice questions i usually visit your website for interview questions etl testing online training. Top sql interview questions you must prepare for 2020 edureka. Etl testing interview questions and answers etl testing is a popular trend today with plenty of job opportunities and attractive salary options.
Guide the recruiter to the conclusion that you are the best candidate for the etl tester job. Two ways to approach data transformation in etl testing are. Etl testing objective type questions and answers list. What is difference between manual testing and etl testing. Here, i have compiled the proven etl interview questions to ask potential prospects that will help you to assess etl skills of applicants. Etl testing 5 both etl testing and database testing involve data validation, but they are not the same. It makes sure that updates and inserts are done as expected during the incremental etl process. And more importantly performance tuning tips given in simple way so that you can learn easily. These are some differences bw manual and etl development. This way, you can position yourself in the best way to get hired.
It starts with the basic sql interview questions and later continues to advanced questions based on your discussions and answers. Here, we have given a complete list of etl testing interview questions and answers for freshers and experienced to help the job seekers in the best way. Mar 28, 2012 sql, sql tutorial, sql server, sql injection, sql joins, sqlite, sql server 2017, sql queries, sql interview questions, sql developer, sql database, sql basics, sql access, sql advanced, sql aggregate functions, sqlalchemy, sql and python, sql attack, sql agent, sql administration, sql assertion, sql and php, sql bucky, sql bi, sql bulk insert, sql bangla tutorial for beginners, sql backup. These sql interview questions are very simple and mainly were used for interviewing software testers who is involved or going to involve in database sql testing or grey box testing. Sql interview questions for testers software testing times. Etl stands for extract transform load and is widely regarded as one of the essential testing tools in the data warehousing architecture.
Basics of etl testing with sample queries datagaps. Having a well defined etl testing strategy can make the testing process much easier. They write the sql queries for the different test scenario. As these tools help in dealing with huge amount of data and historic data, it is necessary to carry out the etl testing. Here are the top 11 sample etl testing interview questions and their answers. In this etl testing process, a group of experts comprising the programming and developing team will start writing sql statements. Etl testing interview questions and answers etl in cts. Mar 20, 2020 an etl testers need to be comfortable with sql queries as etl testing may involve writing big queries with multiple joins to validate data at any stage of etl. Data duplication may also arise due to incorrect mapping, and manual errors. Strong sql scripting etl testing skills, web application testing experience working knowledge of defect management process, risk framework and mitigation, and enterprise testing standards ability to write and understand complex sql queries. Its main task is to handle data management for the businesses process which is complex and are useful to the business in many ways. In my previous articles i explained about different interview questions related to sql. An etl tool is used to extract data from different data sources, transform the data, and load it into a dw system. Etl testing interview questions and answers sql, ibm, informatica.