Database Administration Questions

SQL profiler is a tool to monitor performance of various stored procedures. It is used to debug the queries and procedures. Based on performance, it identifies the slow executing queries. Capture any problems by capturing the events on production environment so that they can be solved.

A Subquery or Inner query or a Nested query is a query within another SQL query and embedded within the WHERE clause.

Subqueries are most frequently used with the SELECT statement. The basic syntax is as follows::

SELECT column_name [, column_name ]
FROM table1 [, table2 ]
WHERE column_name OPERATOR
(SELECT column_name [, column_name ]
FROM table1 [, table2 ]
[WHERE])

A subquery is used to return data that will be used in the main query as a condition to further restrict the data to be retrieved.

Subqueries can be used with the SELECT, INSERT, UPDATE, and DELETE statements along with the operators like =, <, >, >=, <=, IN, BETWEEN, etc.

There are a few rules that subqueries must follow −

1. Subqueries must be enclosed within parentheses.

2. A subquery can have only one column in the SELECT clause, unless multiple columns are in the main query for the subquery to compare its selected columns.

3. An ORDER BY command cannot be used in a subquery, although the main query can use an ORDER BY. The GROUP BY command can be used to perform the same function as the ORDER BY in a subquery.

4. Subqueries that return more than one row can only be used with multiple value operators such as the IN operator.

5. The SELECT list cannot include any references to values that evaluate to a BLOB, ARRAY, CLOB, or NCLOB.

6. A subquery cannot be immediately enclosed in a set function.

7. The BETWEEN operator cannot be used with a subquery. However, the BETWEEN operator can be used within the subquery.

Here all the options given are important functions of Earth's atmosphere.

Data Definition Language (DDL):- are the SQL statements that define the database structure.

Example:

1.  CREATE


2.  ALTER


3.  DROP


4.  TRUNCATE


5.  COMMENT


6.  RENAME

Storage locations and OneDrive are both displayed in File Explorer.

ZIP file is an archive file format that supports lossless data compression. Lossless is a fairly popular data compression method that is used in a number of different applications. Files can become corrupted when they are transferred over the internet in an uncompressed format. It enables devices to transmit or store the same amount of data in fewer bits.

This question is designed to see how well you can mediate a situation and handle conflict. You want to come across as someone who can compromise when necessary. An interviewer wants to see that you can not only reach an outcome that is desirable for both sides of a conflict of interest, but also that you can understand where the other person is coming from. Empathy and understanding go a long way in any job and this is a good opportunity to show that you can put yourself in another’s shoes.