Database Administration Questions

Operating system is the most common type of System software.

Data Control Language (DCL):-statements to take care of the security and authorization.

Examples:

1. GRANT


2. REVOKE

Log shipping defines the process for automatically taking backup of the database and transaction files on a SQL Server and then restoring them on a standby/backup server. This keeps the two SQL Server instances in sync with each other. In case production server fails, users simply need to be pointed to the standby/backup server. Log shipping primarily consists of 3 operations:

Backup transaction logs of the Production server.

Copy these logs on the standby/backup server.

Restore the log on standby/backup server.

Mushroom.

APK stands for Android Application Package.

Android Package (APK) is the package file format used by the Android operating system for distribution and installation of mobile apps and middleware.

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.

The Riddle itself has the Answers.

What is a 4 letter word

Yet is written in 3 letters

Everything is written with 9 letters

Then with 4 letters

Rarely has 6 letters

Never is written in 5 letters.

Ctrl + F is a shorcut keyword and it is used for searching the word you want in the large document in the M.S. Word.