Top Questions About SQL Server at Job Interviews
A server gives users access to a central network where they can share and use the same resources. A SQL server, on the other hand, is only for data architecture, which is an important part of infrastructure and a key resource for enterprise businesses. Because SQL servers are so important to the way many businesses run, it’s important to hire someone who knows and has experience with SQL. With these SQL server interview questions and answers, we’ll show you how to make yourself stand out as a top candidate. About SQL Server at Job Interviews
What to expect at an interview for SQL server
SQL Server is a data storage server made by Microsoft. It can be used as part of a business’s infrastructure to help it grow and scale. During an interview for SQL Server, candidates should be able to answer both SQL-specific and general database questions. They should be able to talk about their own experiences and explain very technical ideas.
Consider using the STAR method, which stands for Situation, Task, Action, and Result, to answer interview questions about your SQL Server experience. The STAR technique has you think about a difficult situation you faced at work in the past, describe what you did to solve it, explain what steps you took, and show what happened as a result.
General questions
As you prepare for your SQL Server interview, here are some general interview questions to think about:
- Tell me something about you.
- How much do you want to make?
- What is the most satisfying part of working with SQL?
- What do you do well?
- Where do you fall short?
- Why should they hire you for this job?
- Where do you think you’ll be in a year? What’s that? How long?
- What makes you want this job?
- What is your biggest accomplishment at work?
- Describe what your dream job would be like.
Questions about how much you know about and have used SQL Server
Try answering these questions about your experience and background with SQL Server:
- In your experience, what are the most common problems with SQL Server’s performance?
- What do you know about linking servers?
- Tell me about a time you tried to write a query but it didn’t work. What went wrong and how did you fix it?
- Tell me about what you know about SQL Server.
- Tell me about your favorite SQL Server project and why you liked it.
- Tell me about a time when you were in charge of a SQL server and what you had to do.
- Explain in simple terms a SQL Server topic that is hard to understand.
- Which SQL functions do you like the most, and how do you use them?
- What about your past makes you a good candidate for this job?
- Have you ever written a function that is defined by the user?
In-depth questions
Here are some detailed questions that you might need a notebook or portfolio to answer:
- Fix this SQL query problem.
- Explain the difference between logical joins and physical joins.
- What is a SQL stored procedure that calls itself?
- What is a subquery and what does it do?
- What’s the difference between SQL Server’s SUBSTR and CHARINDEX?
- How do you protect SQL from attacks that use injection?
- How do you set up an index for a table? Make a list and describe each one.
- Describe OLTP.
- Explain why mirroring is a good thing.
- What are SQL Server’s different normalization forms?
Answers to the most common SQL Server interview questions
You might get questions about SQL Server that are both common and based on your own experience. You might also get questions that need longer, more in-depth answers. Here are some more in-depth questions you might be asked at your interview, along with tips on how to answer them. Each question needs a multi-step answer:
What kinds of Recovery Models are there in SQL Server, and how are they used?
This question checks how well you know how to recover data in SQL. Big Data is important for business operations, management, and making decisions. Because of this, companies looking to hire a SQL Server developer may have a hard time if they lose data. To answer this question, show how much you know by listing each recovery model and giving a short explanation of what it does.
Example: “When it comes to lost data, it’s important to know how recovery models work. Recovery models are used to do important restoration tasks in SQL Server. One common model of recovery is the full recovery model. Full recovery models let you restore to a certain point in time because they keep track of all operations up to that point. This is the best model for a server that is used in a production environment, but it may cost some performance.
The bulk-logged recovery model is another option. In a bulk-logged recovery model, only the most important data edit functions are kept track of. This makes it easier to keep track of important restoration processes and saves time. But because it logs non-essential operations in bulk, you can’t go back to a certain point in time.
Lastly, the simple recovery model is the simplest and lets you restore your whole database from a backup. You can back up the whole database or just the changes that have been made recently. The second option is more efficient, but it puts you at risk if something goes wrong between backups.”
What are temporary tables, and how do you decide which ones to use?
This question gets right to the heart of what you know about temporary tables. This is a very important way to store data, but it only works for a certain amount of time. When you answer, name the temporary tables in SQL Server and explain what each one does.
Example: “Temporary tables come in three main styles. There are table variables, which can only be seen by the connection that created them and are deleted when the operation is done, local temporary tables, which are similar to variables but are deleted when the connection that created them closes, and a global temporary table, which can be seen by everyone and is deleted when all connections have closed on it.”
Describe physical joints and what they do.
A join is a way to link data from one column or row to data in another table or tables. Joins will likely be important for anyone who works with SQL Server. Because of this, you might be asked to know the three physical joins and how to use them.
Example: “A nested loop compares data from two or more tables, row by row, and connects data when the join predicate is true. SQL experts can do this quickly and well by limiting the number of inner rows in the table that are being compared.
The merge join is useful because it works quickly. Before trying to merge the rows together, this algorithm sorts the data in rows. After the data has been sorted, it is easy to merge rows together.
The hash join algorithm is great for big jobs that don’t have indexes that can be used. In this process, a hash index is made on the left side of a table, and values on the right side of the table are matched to it.”
How are locking, deadlocking, and blocking different from each other? How often do they happen?
When a question asks you to compare two or more things, you can show how much you know about more than one thing. List each item in question and give a short explanation of what makes it different from the others.
Example: “When a user opens a file to edit it, the file is locked. The file can’t be changed by other users until it’s been updated, so that everyone has the latest information. Blocking is the second step in this process. It is a function that stops processes by putting them in a queue. When one thing is done with a record, another can start. When two processes try to finish the same task at the same time and both get stopped by the other, this is called a deadlock.”
Write a SQL server query.
SQL professionals often have to show that they know how to write SQL queries, which is the language used to program a database. Make sure you know how to write complete queries and improve your coding skills before you go to a SQL server interview.
Explain what the SQL Profiler is.
When a company asks you to talk about a certain feature or resource, it’s probably important to the job as a whole. In this case, it’s SQL profiler, but in other situations, you might be asked:
- Stored procedure with a loop
- Subqueries
- Bulkcopy, plus
“SQL Profiler is a tool for keeping an eye on the SQL server that lets administrators save and log events.”
What are the two ways to log in to SQL server?
This question gives you a chance to show that you know about two different ways SQL server developers do things. Name each one and explain how to use it to answer this question.
Example: “Windows mode and Mixed mode are the two ways to sign in. You can choose your mode or change it by going to the SQL server configuration tools menu and selecting the security page option.”
What does CHECK stand for?
This question tests how well you know constraints, which are a basic idea in SQL server. It may be important for the role to know how to use a common method like CHECK.
Example: “When used on columns, the CHECK constraint makes sure that only certain data can be entered. This helps make sure that the data is correct and keeps the database’s integrity.”
What does SQL server’s “scheduled tasks” mean?
Automation is important for large businesses and efficiency as a whole. There are ways to automate SQL Server. One of these options is to do tasks on a set schedule. Look at the example below to see how to answer this question.
“Scheduled tasks are an automation that makes it easier to finish and process tasks because they don’t require as much human interaction.”
Talk about the SQL server agent.
The SQL server agent is an important tool for a SQL database administrator to use in their daily work. To show you know about the server agent, give a short answer that accurately describes what the SQL server agent does.
“The server agent is the automation tool that lets database users set tasks to run at a certain time.”
Explain what the COALESCE function does.
SQL server has a number of important functions, and we’ll talk about one of them below. By showing that you know how things work, you can show that you have a practical understanding of the system. You might also be asked about these other important tasks:
- Use of a sign
- The floor’s job
“COALESCE returns the first non-null value in an expression,” for example.
What does the word “trigger” mean in SQL server?
Triggers are an important part of technology that are used to put code into action. They are one of the most important ideas in SQL server. This question gives you a chance to show that you know what triggers are.
Example: “A trigger is a process that runs SQL code to do things like edit or delete records. When records in a SQL database are changed, triggers are automatically run.”
Which four types of triggers are there?
By listing the different kinds of triggers, you can show that you know more about this idea.
“Insert, Instead of, Update, and Delete are the four types of triggers.”
