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The best way to retrieve matching rows from two tables is using an inner join. It will return records that have the same value in both tables.

Syntax: 

Example: LET's take two tables called InterviewBit and Scaler. The first table, called InterviewBit, contains the following data.

The second table, called Scaler, contains the following data.

SQL Statement:

Output:

As seen in the output, the SQL query returns all rows from the InterviewBit and Scaler tables where Employee_Id values match in both tables.

Application Support Engineers are technical professionals responsible for resolving software application errors within an organization and ensuring optimal application performance at the company. In particular, for businesses with a digital presence, application support engineers are an essential component of customer service and customer service has a tremendous impact on a business's reputation. Companies are therefore eager to hire qualified applications engineers and analysts to join their IT and customer service departments.

Application Support Interview QUESTIONS, like those listed above, are quick and INSIGHTFUL, and they PROVIDE a wealth of INFORMATION that is vital to the interview process. Hopefully, we have clarified your doubts and guided you in the right direction. Wishing you good luck.

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In SQL, join STATEMENTS combine data from multiple tables BASED on a common field between them. Any time there are two or more tables listed in a SQL statement, a SQL JOIN is performed. Among the DIFFERENT types of joins are:

• INNER JOIN: It will return records that have the same value in both tables. In this case, it would return records where TABLE1 and table2 intersect. Below is a visual representation of the same.

• LEFT (Outer) JOIN: It will return all records from the left-hand table, along with matched records from the right-hand table. It would return all records from table1 (left-hand table) and only those records from table2 (right-hand table) that intersect with table1. Below is a visual representation of the same.

• RIGHT (Outer) JOIN: It will return all records from the right-hand table, along with matched records from the left-hand table.  It would return all records from table2 (right-hand table) and only those records from table1 (left-hand table) that intersect with table2. Below is a visual representation of the same.

• FULL (Outer) JOIN: It will return all records from both left-hand and right-hand tables. It would return all rows from both the left-hand table (table1) and right-hand table (table2) with NULL values in place wherever the join condition is not satisfied. Below is a visual representation of the same.

The P1 status indicates a complete outage / significant traffic impact. It involves any failure of IT services that will lead to immediate and severe consequences in TERMS of corporate IMAGE, financial losses, or loss of accreditation. For example, an entire website might be down or a critical infrastructure component may be down or its performance has been impacted. 

It is always critical to have the names and contacts of dependent services accessible so that they may be contacted right away in case of a P1 emergency. To RECTIFY any issues, you must examine all configurations, and databases, and troubleshoot them appropriately. If TWO P1 issues occur at the same time, you must prioritize them. In that case, you should inform higher management and request quick resource allocation if both issues have the POTENTIAL to affect business operations.

SUPPORT analysts are primarily RESPONSIBLE for prioritizing work based on business impact. It's important to give the highest priority to customer REQUESTS that have a significant impact on our business. We should resolve the issue first, and then log it into the issue MANAGEMENT SYSTEM.

In any organization, "the customer is king." That means some time MUST be allocated to DEALING with customer ISSUES. You never know what the customer might ask you. It might be an ad-hoc ISSUE. Nevertheless, we should resolve the issue first, and then LOG it into the issue management system. It will show your efforts and time spent on customer issues.

By USING the LS command, you can list down the current DIRECTORY’s content LIKE files and folders.

Syntax: 

With no arguments and no options, ls displays a list of all files in the current working directory:

Examples:

• List the names of the files in your current directory alphabetically
• Command

Output

Files are arranged in alphabetical order across as many columns as your terminal can accommodate.

• To view all information about a files/directory
• Command

Output

Switching between user accounts is accomplished by using the SU (Substitute User or Superuser) command. With the su command, you can execute functions or commands with another user's PRIVILEGES or as a DIFFERENT user, by default the root user. When running su, you must enter the password of the user you want to switch to.

Syntax: 

Without any options, su will run an interactive shell as a superuser (root).

Example: 

Upon EXECUTION of su, it will ask for the password of the target user. If authenticated, it will GRANT access to the target user's account, as well as any files and directories the target user has access to.

• Current directory (.): In Unix, (.) DENOTES the current directory. Using the COMMAND "cd ." (with a space between cd and dot), you will remain where you are.
• Parent directory (..): In Unix, (..) denotes the parent of the current directory. Using the command "cd.." or "cd .." (with a space), you move the directory BACK to ONE directory. This is also known as moving to the parent directory. For instance, if you're in the /home/gourav directory, using the "cd.." command takes you back to the home directory.

YES, we can delete multiple files at once in Unix. The rm command (short for remove) is a command USED in Unix and Unix-like systems to delete or remove files, directories, or symbolic LINKS from FILE systems. Like other commands, rm has options that specify how it should behave. Some of the options are as follows:

• rm -i: It asks for CONFIRMATION before deleting a file.
• rm -f: It ignores non-existing files and overrides any confirmation prompts.
• rm -r: It removes or deletes directories along with their contents recursively.

Syntax (to delete multiple files at once):

Among the most commonly used and most secure operating systems in application development and deployment is Unix. 90% of applications run on UNIX SERVERS because of their security. It is SIMPLE, stable, has better scalability, supports multi-user and multi-tasking FUNCTIONALITY, as well as being used in all forms of computing systems such as desktops, laptops, and servers. Therefore, having a good knowledge of Unix WOULD be helpful.

In a SQL statement, a comment can be inserted between keywords, parameters, or punctuation marks. To add a comment to your SQL statement in Oracle/PLSQL, you have two options.

• Single Line comment (--): In your SQL statement, you can begin the comment with two HYPHENS (--) at the END of the line and proceed with the comment text. Comment text cannot go beyond one line. The comment MUST be terminated with a line break.
  • Syntax: 

• Multi-line comment (/* */): In your SQL statement, you can begin the comment with a SLASH and an asterisk (/*) at the end of the line and proceed with the comment text. Comment text may span multiple lines, i.e., it can go beyond one line. The comment must be terminated with an asterisk and a slash (*/). There is no need to separate the opening and closing CHARACTERS with a space or a line break.
  • Syntax: 

In application support, there are SEVERAL tools for tracking and managing ISSUES, and therefore, an application support ENGINEER must have extensive knowledge of these tools. These tools may include:

• IT management software
• Complex COMPUTER systems
• Telecommunications systems
• Photocopier machine and printers

Day-to-day RESPONSIBILITIES of an application SUPPORT ENGINEER include:

• Attend scheduled meetings with other IT professionals so they can discuss certain issues that have arisen and those that need to be addressed. 
• Managing application issues and fixing system problems. 
• Resolve technical issues as soon as possible. 
• Track issue triage as troubleshooting progresses.
• Provide training to different teams within the organization.
• Prepare and MAINTAIN service REPORTS.