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Etl Testing Questions And Answers Pdf

etl testing questions and answers pdf

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ETL stands for Extract-Transform-Load and it is a process of how data is loaded from the source system to the data warehouse. Data is extracted from an OLTP database, transformed to match the data warehouse schema and loaded into the data warehouse database. There are many jobs on ETL testing some of the most popular jobs in it are software engineer, QA analyst, ETL test engineer, quality analyst, manual tester, ETL developer, data engineer, data consultant, python developer, data lead, ETL architect, integration engineer, big data developer and analyst etc. Answer : ETL stands for extraction, transformation and loading.

ETL Testing Interview Questions and Answers

Following are frequently asked questions in interviews for freshers as well experienced ETL tester and developer. In data warehousing architecture, ETL is an important component, which manages the data for any business process.

Extract does the process of reading data from a database. Transform does the converting of data into a format that could be appropriate for reporting and analysis. While, load does the process of writing the data into the target database.

ETL testing 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 Make sure that ETL application reports invalid data and replaces with default values Make sure that data loads at expected time frame to improve scalability and performance 3 Mention what are the types of data warehouse applications and what is the difference between data mining and data warehousing?

The types of data warehouse applications are Info Processing Analytical Processing Data Mining 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 4 What are the various tools used in ETL?

What are the types of facts? It is a central component of a multi-dimensional model which contains the measures to be analysed.

Facts are related to dimensions. Cubes are data processing units comprised of fact tables and dimensions from the data warehouse. It provides multi-dimensional analysis. It consists of facts called as measures categorized by dimensions. Tracing level is the amount of data stored in the log files. Tracing level can be classified in two Normal and Verbose. Normal level explains the tracing level in a detailed manner while verbose explains the tracing levels at each and every row.

Grain fact can be defined as the level at which the fact information is stored. It is also known as Fact Granularity 9 Explain what factless fact schema is and what is Measures? A fact table without measures is known as Factless fact table. It can view the number of occurring events. For example, it is used to record an event such as employee count in a company. The numeric data based on columns in a fact table is known as Measures 10 Explain what is transformation?

A transformation is a repository object which generates, modifies or passes data. The Lookup Transformation is useful for Getting a related value from a table using a column value Update slowly changing dimension table Verify whether records already exist in the table 12 Explain what is partitioning, hash partitioning and round robin partitioning? To improve performance, transactions are sub divided, this is called as Partitioning.

Partioning enables Informatica Server for creating of multiple connection to various sources The types of partitions are Round-Robin Partitioning: By informatica data is distributed evenly among all partitions In each partition where the number of rows to process are approximately same this partioning is applicable Hash Partitioning: For the purpose of partitioning keys to group data among partitions Informatica server applies a hash function It is used when ensuring the processes groups of rows with the same partitioning key in the same partition need to be ensured 13 Mention what is the advantage of using DataReader Destination Adapter?

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. 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 16 In what case do you use dynamic cache and static cache in connected and unconnected transformations?

Dynamic cache is used when you have to update master table and slowly changing dimensions SCD type 1 For flat files Static cache is used 17 Explain what are the differences between Unconnected and Connected lookup?

Connected Lookup Unconnected Lookup Connected lookup participates in mapping - It is used when lookup function is used instead of an expression transformation while mapping Multiple values can be returned - Only returns one output port It can be connected to another transformations and returns a value Another transformation cannot be connected Static or dynamic cache can be used for connected Lookup Unconnected as only static cache Connected lookup supports user defined default values Unconnected look up does not support user defined default values In Connected Lookup multiple column can be return from the same row or insert into dynamic lookup cache Unconnected lookup designate one return port and returns one column from each row 18 Explain what is data source view?

A data source view allows to define the relational schema which will be used in the analysis services databases. Rather than directly from data source objects, dimensions and cubes are created from data source views. The difference between ETL and OLAP tool is that ETL tool is meant for the extraction of data from the legacy systems and load into specified data base with some process of cleansing data.

Example: Data stage, Informatica etc. Example: Business Objects, Cognos etc. It does not support ERP sources It supports local and global repository It supports local repository It converts local into global repository It has no specification to convert local into global repository 22 Explain what staging area is and what is the purpose of a staging area?

Data staging is an area where you hold the data temporary on data warehouse server. Data staging includes following steps Source data extraction and data transformation restructuring Data transformation data cleansing, value transformation Surrogate key assignments 23 What is Bus Schema?

For the various business process to identify the common dimensions, BUS schema is used. It comes with a conformed dimensions along with a standardized definition of information 24 Explain what is data purging? Data purging is a process of deleting data from data warehouse. It deletes junk data's like rows with null values or extra spaces. Schema objects are the logical structure that directly refer to the databases data.

Schema objects includes tables, views, sequence synonyms, indexes, clusters, functions packages and database links 26 Explain these terms Session, Worklet, Mapplet and Workflow? What is Database? A database is a collection of related data which represents some elements of the What is Data Mining?

Data Mining is a process of finding potentially useful patterns from huge What is OLAP? What is Data Modelling? Data modeling data modelling is the process of creating a data model for the What is Information? Information is a set of data that is processed in a meaningful way according to Home Testing. Must Learn! Big Data. Live Projects. What is DataStage? Datastage is an ETL tool which extracts data, transform and load data from In Connected Lookup multiple column can be return from the same row or insert into dynamic lookup cache.

Unconnected lookup designate one return port and returns one column from each row.

Top ETL Testing Interview Questions and Answers

Explore Now! We hope these ETL Testing Interview Questions and answers are useful and will help you to get the best job in the networking industry. These questions and answers are suitable for both freshers and experienced professionals at any level. ETL testing applies to Data Warehouses or Data joining ventures while Database Testing applies to any database holding information regularly exchange frameworks. Here are the abnormal state tests done in each:. ETL Testing: Primary objective is to check if the information moved appropriately not surprisingly.

There are a lot of opportunities from many reputed companies in the world. According to research ETL Testing has an extension market share. This course will help you to achieve excellence in this domain. Q1 What exactly do you mean by ETL? Ans: ETL stands for Extract Transform Load and is widely regarded as one of the essential Testing tools in the data warehousing architecture. Its main task is to handle data management for the business process which is complex and is useful to the business in many ways. Extracting simply means reading the data from a database.


ETL Testing Interview Questions - Learn about ETL Testing Interview Questions and Answers for Both Freshers and Experienced. Check Out Now!


Top 25 ETL Testing Interview Questions & Answers

Basic Interview Questions

Here are the top 11 sample ETL Testing interview questions and their answers. We have taken full care to give the best answers to all the questions. Do comment your thoughts! If you are a fresher or a professional and looking for a platform to prepare for job interviews in ETL Testing, then this is the right place for you. It guides you through the basic-to-advanced level questions that are generally asked during job interviews in this field.

Беккер покровительственно улыбнулся и перевел взгляд на дверь в ванную. - А у Росио. Капельки Росы. Лицо мужчины из мертвенно-бледного стало красным. - Вы знаете Капельку Росы? - Вытерев пот со лба рукавом халата, он собирался что-то сказать, но тут отворилась дверь в ванную.

Стратмор задумался. - Должно быть, где-то замыкание. Желтый сигнал тревоги вспыхнул над шифровалкой, и свет, пульсируя, прерывистыми пятнами упал налицо коммандера. - Может, отключить его самим? - предложила Сьюзан. Стратмор кивнул. Ему не нужно было напоминать, что произойдет, если три миллиона процессоров перегреются и воспламенятся.

 - Червь… я знаю, на что он запрограммирован! - Она сунула распечатку Джаббе.  - Я поняла это, сделав пробу системных функций. Мы выделили отдаваемые им команды - смотрите.

 - Сьюзан пожала плечами, демонстрируя равнодушие. - Мы с ним какое-то время переписывались, - как бы невзначай сказал Хейл.  - С Танкадо. Ты знала об. Сьюзан посмотрела на него, стараясь не показать свое изумление.

В эпоху цифровой связи понятие неприкосновенности частной жизни ушло в прошлое. Записывается. Телефонные компании могут сообщить, кто вам звонил и как долго вы говорили.

 - Мидж полистала страницы.  - Ни вчера, ни. Бринкерхофф пожал плечами: - Быть может, ребята заняты сложной диагностикой. Мидж покачала головой: - Настолько сложной, что она длится уже восемнадцать часов? - Она выдержала паузу.  - Маловероятно.

ETL Testing Interview Questions

 Итак, вы хотите продать ключ, имеющийся в вашем распоряжении. Интересно. А что по этому поводу думает Энсей Танкадо. - Я ничем не обязан мистеру Танкадо. Он зря мне доверился.

Увы, ее руки уперлись в холодное стекло. Хейл с перепачканным кровью лицом быстро приближался к. Его руки снова обхватили ее - одна сдавила левую грудь, другая - талию - и оторвали от двери. Сьюзан кричала и молотила руками в тщетной попытке высвободиться, а он все тащил ее, и пряжка его брючного ремня больно вдавливалась ей в спину.

Могли сбой произойти внезапно, сам по. Размышляя об этом, Сьюзан вдруг вспомнила фразу, сказанную Стратмором: Я попытался запустить Следопыта самостоятельно, но информация, которую он выдал, оказалась бессмысленной. Сьюзан задумалась над этими словами.

 - Танкадо избавился от кольца. Он хотел, чтобы оно оказалось как можно дальше от него - чтобы мы его никогда не нашли.

5 Comments

  1. Denis Г.

    23.12.2020 at 10:25
    Reply

    It is an essential concept in Data Warehousing systems.

  2. Paul H.

    24.12.2020 at 17:50
    Reply

    Following are frequently asked questions in interviews for freshers as well experienced ETL tester and developer.

  3. Melizabeth

    28.12.2020 at 09:31
    Reply

    Additionally, our ETL Testing Online Training will help for the bright future of the learners as data is growing rapidly and many technologies are making use of data.

  4. Jewel P.

    29.12.2020 at 12:07
    Reply

    Top 25 ETL Testing Interview Questions & Answers · 1) What is ETL? · 2) Explain what are the ETL testing operations includes? · 3) Mention what.

  5. Aylen R.

    29.12.2020 at 20:00
    Reply

    In data warehousing architecture, ETL is an important component, which manages the data for any business process.

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