Data Engineer Interview Questions And Answers

Want You To Write Me A Simple Spell Checking Enginethe Query Language Is A Very Simple Regular Expression

Here is the Python Code :def setUp: word = word.strip temp_list = Ismatch = False if word in input_list: Ismatch = True elif word is None or len == 0: Ismatch = False else: for w in input_list: if len == len: temp_list.append for j in range): count=0 for i in range): if word == temp_list or word == ‘.’: count += 1 else: break if count == len: Ismatch = True printdef isMatch: return setUpisMatchLess

bear in mind for your solution, checking the lengths of words in the dictionary is very fast. That’s what you can use your setup for. There’s no need to iterate through the whole loop of checks if the word fails the length already. See my solution aboveLess

This was the fastest I could do without regex:def func: if len not in : return False elif wrd in lst: return True else: lst1 = for z in lst1: c=0 for i in range): if wrd != ‘.’ and wrd == z: c=c+1 if len-wrd.count == c: return True return FalseLess

List The Data Masking Features Azure Has

When it comes to data security, dynamic data masking has several vital roles and contains sensitive data to a certain specific set of users. Some of its features are:

• Itâs available for Azure SQL Database, Azure SQL Managed Instance, and Azure Synapse Analytics.
• It can be carried out as a security policy on all the different SQL databases across the Azure subscription.
• The levels of masking can be controlled per the users’ needs.

Data Engineer Interview Questions On Sql

You will spend most of your career using SQL if you are a Data Engineer working in an organization. Building a strong foundation in SQL is crucial since you may easily save time and effort if you can leverage its various features effectively. Also, acquire a solid knowledge of databases such as the NoSQL or Oracle database. Questions addressing data modeling and database architecture test your understanding of entity-relationship modeling, normalization and denormalization, dimensional modeling, and relevant ideas. Below are a few data engineer interview questions on SQL concepts, queries on data storage, data retrieval, and a lot more.

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Write A Query On The Given Tables To Get The Car Model With The Fastest Average Times For The Current Day

In this two-part table schema question, were tracking not just enter/exit times, but also car make, model and license plate info.

The car model to license plate information will be one-to-many, given that each license plate represents a single car, and a car model can be replicated many times. Heres an example for crossings and model/license plate :

Have You Ever Introduced New Data Analytics Apps In Your Field Of Work If Yes What Difficulties Did You Have In Adopting And Executing Them

Because new data applications are expensive, rarely are they used. Explain a scenario that forced you to introduce new data applications.

Sample Answer

As a data engineer, I assisted in the introduction of a brand-new data analytics program at my former employer. To transition smoothly, the entire process necessitates a well-thought-out plan. Even the most meticulous planning, however, cannot eliminate the possibility of unanticipated complications. One of them was the strong demand for user licenses, which exceeded our expectations. To get more licenses, the corporation had to reallocate financial resources.

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Behavioral Data Engineer Questions

Behavioral data engineer interview questions give the interviewer a chance to see how you have handled unforeseen data engineering issues or teamwork challenges in your experience. The answers you provide should reassure your future employer that you can deal with high-pressure situations and a variety of challenges. Here are a few examples to consider in your preparation.

12. Data maintenance is one of the routine responsibilities of a data engineer. Describe a time when you encountered an unexpected data maintenance problem that made you search for an out-of-the-box solution”.

How to Answer

Usually, data maintenance is scheduled and covers a particular task list. Therefore, when everything is operating according to plan, the tasks dont change as often. However, its inevitable that an unexpected issue arises every once in a while. As this might cause uncertainty on your end, the hiring manager would like to know how you would deal with such high-pressure situations.

Answer Example

Its true that data maintenance may come off as routine. But, in my opinion, its always a good idea to closely monitor the specified tasks. And that includes making sure the scripts are executed successfully. Once, while I was conducting an integrity check, I located a corrupt index that could have caused some serious problems in the future. This prompted me to come up with a new maintenance task that prevents corrupt indexes from being added to the companys databases.

How to Answer

How Would You Debug What Happened What Data Would You Look Into And How Would You Find Out Who Is Actually Married And Who Is Not

With this debugging data question, you should start with some clarification, e.g. how far back does the bug extend? Whats the table schema like? One potential solution would be to look at other dimensions and columns that might be able to answer if someone is actually married .

This question has been asked in .

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Explain Macros In Excel

Macros in Excel refers to an action or a set of actions that can be saved and recorded to run as often as required. Macros may be given names and can be used to save time to perform any frequently run tasks. Excel stores macros as VBA code, and you can view the code using a VBA editor. You can assign macros to objects, including shapes, graphics, or control.

Data Engineer Interview Questions And Answers 2021

Data engineer interview questions are a major component of your interview preparation process. However, if you want to maximize your chances of landing a data engineer job, you must also be aware of how the data engineer interview process is going to unfold.

This article is designed to help you navigate the data engineer interview landscape with confidence. Heres what you will learn:

• the most important skills required for a data engineer position
• a list of real data engineer questions and answers
• how the data engineer interview process goes down in 3 leading companies.

As a bonus, well reveal 3 common mistakes you should avoid at all costs during your data engineer interview questions preparation.

But first things first

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In Brief What Is The Difference Between A Data Warehouse And A Database

When working with Data Warehousing, the primary focus goes on using aggregation functions, performing calculations, and selecting subsets in data for processing. With databases, the main use is related to data manipulation, deletion operations, and more. Speed and efficiency play a big role when working with either of these.

Questions About Experience And Background

The following background and experience questions help the hiring team evaluate your qualifications and assess whether your goals are in line with the organization’s values and objectives:

• What would you bring to our organization?

• What do you like most about your current job?

• What do you like least about your current position?

• Tell us about your data engineering work experience.

• What do you appreciate most about data engineering?

• What do you enjoy least about data engineering?

• Can you describe your biggest accomplishment?

• What is your preferred work environment?

• Are you comfortable with reporting to superiors younger than you?

• Do you consider yourself a leader?

• What is your definition of professional success?

• How do you envision your career path?

• Where do you see yourself in five years?

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Skipping The Mock Interview

Are you so deep into your interview preparation process that youve cut all ties with the outside world? Big mistake! Snap out of it now, call a fellow data engineer and ask them to do a mock interview with you. Every interview has a performance side to it, and just imagining how youre going to act or sound wouldnt give you a realistic idea. So, while youre doing the mock interview, pay special attention to your body language and mannerisms, as well as to your tone of voice and pace of speech. Youll be amazed by the insight youre going to get!

More Case Study Questions

71. How would you build a data pipeline that data that originates at POS systems?

72. Design an ETL to process a billion events every day and generate a daily report.

73. What database optimizations might you consider for a Tinder-style app?

74. How would you design a relational database of customer data?

75. How do you go about debugging an ETL error?

76. Whats your approach to design methodologies and design patterns?

77. What architectural patterns do you have the most experience with?

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You Have A Table With A Billion Rows How Would You Add A Column Inserting Data Without Affecting User Experience

Many database design questions for data engineers are vague, and require a follow up. With a question like this, you might want to ask:

• Whats the potential impact of downtime?

Dont rush into answers to questions. A helpful tip for all Python and technical questions is to ask for more information. This shows youre thoughtful and look at problems from every angle.

What Are The Various Design Schemas In Data Modeling

There are two fundamental design schemas in data modeling: star schema and snowflake schema.

• Star Schema- The star schema is the most basic type of data warehouse schema. Its structure is similar to that of a star, where the star’s center may contain a single fact table and several associated dimension tables. The star schema is efficient for data modeling tasks such as analyzing large data sets.

• Snowflake Schema- The snowflake schema is an extension of the star schema. In terms of structure, it adds more dimensions and has a snowflake-like appearance. Data is split into additional tables, and the dimension tables are normalized.

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What Skills Do You Need To Become A Data Engineer

Skills and qualifications are the most crucial part of your preparation for a data engineer position. Here are the top 5 must-have skills for anyone aiming for a data engineer career:

• Knowledge of data modeling for both data warehousing and Big Data
• Experience in ETLs
• Data visualization skills .

If you need to improve your skillset to launch a successful career as a data engineer, you can register for the complete 365 Data Science Program today. Start with the fundamentals with our Statistics, Maths, and Excel courses, and build up step-by-step experience with SQL, Python, R, Power BI and Tableau.

What Is Your Understanding Of This Job Role

Hiring teams may answer questions related to the job role to understand your preparedness and interest in the job position. When answering this question, including some of the job responsibilities you are likely to complete as a data engineer. If you have previous experience, list some duties you completed in the previous role.

Example:âData engineer collect, organise and analyse data while interpreting trends and patterns. As a data engineer in my previous role, I assessed the need and requirements and and pipelines based on that. I also created various analytical tools and programs. A part of my work duty involved coordinating with web designers, architects and data analysts.â

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How Do You Handle Duplicate Data In Sql

You might want to clarify a question like and ask some follow-up questions of your own. Specifically, you might be interested in A. what kind of data is being processed, B. and what types of values are most likely to be duplicated.

With some clarity, youll be able to suggest more relevant strategies. For example, you might propose using the DISTINCT or UNIQUE key to reduce duplicate data. Or you could walk the interviewer through how the GROUP BY key could be used.

What Is The Linked Service In The Azure Data Factory

Linked service is one of the components in the Azure data factory which is used to make a connection hence to connect to any of the data sources you have to first create the linked service based upon the type of data source. The linked service could have different parameters for example in the case of the SQL Server linked service you probably have to give the server name, username, and password but for connecting to the Azure blob storage you have to give the storage location details.

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What Methods Does Reducer Use In Hadoop

The three primary methods to use with reducer in Hadoop are as follows:

• setup: This function is mostly useful to set input data variables and cache protocols.

• cleanup: This procedure is useful for deleting temporary files saved.

• reduce: This method is used only once for each key and is the most crucial component of the entire reducer.

What Are The Sample Questions In This Book

• What is the difference between ROLLBACK TO SAVEPOINT and RELEASE SAVEPOINT?
• How will you see the current user logged into MySQL connection?
• Can we create multiple tables in Hive for a data file?
• Can we use Hive for Online Transaction Processing systems?
• Can we use same name for a TABLE and VIEW in Hive?
• How can we get a random number between 1 and 100 in MySQL?
• How can you copy the structure of a table into another table without copying the data?
• How can you find 10 employees with Odd number as Employee ID?
• How does CONCAT function work in Hive?
• How will you change the data type of a column in Hive?
• How will you check if a file exists in HDFS?
• How will you check if a table exists in MySQL?
• How will you run Unix commands from Hive?
• How will you search for a String in MySQL column?
• How will you see the structure of a table in MySQL?
• How will you select the storage level in Apache Spark?
• How will you synchronize the changes made to a file in Distributed Cache in Hadoop?
• If we set Replication factor 3 for a file, does it mean any computation will also take place 3 times?
• Is it safe to use ROWID to locate a record in Oracle SQL queries?
• What are different Persistence levels in Apache Spark?
• What are the common Transformations in Apache Spark?

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What Is A Foreign Key In Sql

A foreign key is a field or a collection of fields in one table that can refer to the primary key in another table. The table which contains the foreign key is the child table, and the table containing the primary key is the parent table or the referenced table. The purpose of the foreign key constraint is to prevent actions that would destroy links between tables.

How Can You Identify Missing Values In A Data Frame

The isnull function help to identify missing values in a given data frame.

The syntax is DataFrame.isnull

It returns a dataframe of boolean values of the same size as the data frame in which missing values are present. The missing values in the original data frame are mapped to true, and non-missing values are mapped to False.

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Discuss The Different Windowing Options Available In Azure Stream Analytics

Stream Analytics has built-in support for windowing functions, allowing developers to quickly create complicated stream processing jobs. Five types of temporal windows are available: Tumbling, Hopping, Sliding, Session, and Snapshot.

• Tumbling window functions take a data stream and divide it into discrete temporal segments, then apply a function to each. Tumbling windows often recur, do not overlap, and one event cannot correspond to more than one tumbling window.

• Hopping window functions progress in time by a set period. Think of them as Tumbling windows that can overlap and emit more frequently than the window size allows. Events can appear in multiple Hopping window result sets. Set the hop size to the same as the window size to make a Hopping window look like a Tumbling window.

• Unlike Tumbling or Hopping windows, Sliding windows only emit events when the window’s content changes. As a result, each window contains at least one event, and events, like hopping windows, can belong to many sliding windows.

• Session window functions combine events that coincide and filter out periods when no data is available. The three primary variables in Session windows are timeout, maximum duration, and partitioning key.

• Snapshot windows bring together events having the same timestamp. You can implement a snapshot window by adding System.Timestamp to the GROUP BY clause, unlike most windowing function types that involve a specialized window function ).

What Is A Namenode And How Does A Namenode Crash Affect You

Such data engineer interview questions determine the technical prowess of the interviewee.

Sample Answer: NameNodes keep the metadata of the files on the cluster. Essentially, metadata includes pieces of information such as block location, file size, and hierarchy. It’s analogous to a File Allocation Table , which keeps track of the data blocks that make up files and where they’re kept on a single machine. For a distributed file system, NameNodes store the same information.

Under typical conditions, a NameNode crash will result in data loss, even if all data blocks are intact. In a high-availability system, a passive NameNode backs up the primary one and takes over if the primary one fails.

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