When you are going to attend the ETL interview, you get puzzled about how to answers the questions that will ask by the interviewer. To make this task easier and flawless, the article has assembled a list of questions where you will find the top 10 ELT testing interview questions and answers, which will give you a quick way to read and learn these. These have designed in a very precise and influencing way; thereby, the interviewee will able to answer confidently, quickly, and impressively.
Since there are many questions related to the ETL interview, the following assembled is the best and perfect to go through as these have been asked as of now. Concisely, you must give top-priority to these and read them comprehensively.
Answer: The term ETL stands for Extract, Transform, and Load. This software is used for data need to analyze and forecast the future of any business. ETL comprises three-term; all have different meanings and functions.
Answer: The role of the surrogate key is to model any object or entity. It regarded as the unique key intended to know about the primary identifier of any entity or object that not derived from other databases. Besides, a surrogate key is not always determined as a primary key, and its’ all relied on the database. Its’ depending upon the situation of the database if it is a current kind, then storage will be given to the current database, and it always has a one to one relationship between the primary and surrogate keys while if it is temporal kind, then there will be many to one relationship between the surrogate key and primary.
Q3: What is partitioning, hash partitioning, and round-robin partitioning?
With an intention is to improve performance, transactions get subdivided, which is called partitioning. It allows the Informatica server to establish a multitude of links to different sources. There are two types of partitioning:
Hash partitioning used to partition keys in favor of group data in the middle of the partitions Informatica server when the hash function is applied. Briefly, it used to enables the groups of rows with a similar partitioning key in the similar partition required to be secured.
Round-Robin partitioning is used to divide the Informatica data evenly to all partitions. It used only where the number of rows is similar to the process.
Answer: In a multi-dimensional model, a fact determined at the central part, having all the measures required to be analyzed. There are three types of facts:
Answer: The term data sagging used when there is a need to assemble the processes required to prepare the source system data, which is further loaded or transferred into the data warehouse.
Q7. What is a slow-changing dimension?
Answer: This question is often asked during the interview process, and only a few know about it. The purpose of a slowly changing dimension means it tends to change very slowly or steadily. It means the data available in this process will alter or amend very slowly as compared to others.
Q8: What are the types of data warehouse applications and also explain the difference between data mining and data warehousing?
Answer: There are three types of data warehouse applications have, such as:
The primary difference between data mining and data warehousing is in the case of data mining; there is a process of fetching hidden predictive information from the massive databases while data warehousing used for analytical processing of the data in a steady way. Moreover, data warehousing is used to collect data from a multitude of sources into a single repository.
Q9: What are Cubes and OLAP Cubes?
Cubes are those data processing units that included fact tables and dimensions used to provide multi-dimensional analysis. OLAP or Online Analytics Processing used to store massive data in a multi-dimensional form for report purposes.
Q10: What are the ways of updating a table when SSIS is being used?
Answer: When there is a need for uploading tables when SSIS is being used, the following process has been applied:
The above-written questions are those who have been asked frequently during the ETL testing interview. If you read and learn these questions carefully, you will influence the interviewer.
All the best!
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