41.What are the security alerts while using MySQL?

Install antivirus and configure the operating system's firewall. Never use the MySQL Server as the UNIX root user. Change root username and password Restrict or disable remote access.

42.How to change a password for an existing user via Mysqladmin?

Mysqladmin -u root -p password "newpassword".

43.What is the difference between Unix timestamps and MySQL timestamps?

Actually both Unix timestamp and MySQL timestamp are stored as 32-bit integers but MySQL timestamp is represented in readable format of YYYY-MM-DD HH:MM:SS format.

44.What is MySQL default port number?

MySQL default port number is 3306.

45.What is REGEXP?

REGEXP is a pattern match using regular expression. Regular expression is a powerful way of specifying a pattern for a complex search.

46.How many columns can you create for an index?

You can create maximum of 16 indexed columns for a standard table.

47.What is the difference between NOW() and CURRENT_DATE()?

NOW() command is used to show current year, month, date with hours, minutes and seconds while CURRENT_DATE() shows the current year with month and date only.

48.Write a query to display current date and time?

If you want to display current date and time, use -

• SELECT NOW();
• If you want to display current date only, use -

49.What is save point in MySQL?

A defined point in any transaction is known as savepoint. SAVEPOINT is a statement in MySQL which is used to set a named transaction save point with a name of identifier.

50.What is SQLyog?

SQLyog program is the most popular GUI tool for admin. It is the most popular MySQL manager and admin tool. It combines the features of MySQL administrator, phpMyadmin and others MySQL front ends and MySQL GUI tools.

51.How do you backup a database in MySQl?

It is easy to backing up data with phpMyAdmin. Select the database you want to backup by clicking the database name in the left hand navigation bar. Then click the export button and make sure that all tables are highlighted that you want to backup. Then specify the option you want under export and save the output.

52.What is MySQL?

MySQL is an open source DBMS which is built, supported and distributed by MySQL AB (now acquired by Oracle)

53.What are the technical features of MySQL?

MySQL database software is a client or server system which includes

• Multithreaded SQL server supporting various client programs and libraries
• Different backend
• Wide range of application programming interfaces and
• Administrative tools.

54.Why MySQL is used?

MySQL database server is reliable, fast and very easy to use. This software can be downloaded as freeware and can be downloaded from the internet.

55.What are Heap tables?

HEAP tables are present in memory and they are used for high speed storage on temporary basis.

• BLOB or TEXT fields are not allowed
• Only comparison operators can be used =, <,>, = >,=<
• AUTO_INCREMENT is not supported by HEAP tables
• Indexes should be NOT NULL

56.What is the default port for MySQL Server?

The default port for MySQL server is 3306.

57.What are the advantages of MySQL when compared with Oracle?

• MySQL is open source software which is available at any time and has no cost involved.
• MySQL is portable
• GUI with command prompt.
• Administration is supported using MySQL Query Browser

58.Differentiate between FLOAT and DOUBLE?

Following are differences for FLOAT and DOUBLE:

• Floating point numbers are stored in FLOAT with eight place accuracy and it has four bytes.
• Floating point numbers are stored in DOUBLE with accuracy of 18 places and it has eight bytes.

59.Differentiate CHAR_LENGTH and LENGTH?

CHAR_LENGTH is character count whereas the LENGTH is byte count. The numbers are same for Latin characters but they are different for Unicode and other encodings.

60.How to represent ENUMs and SETs internally?

ENUMs and SETs are used to represent powers of two because of storage optimizations.