MySQL Interview Questions and Answers Part-1
MySQL is an open source DBMS which is built, supported and distributed by MySQL AB (now acquired by Oracle)
2. 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
Wide range of application programming interfaces and
3. 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.
4. What are Heap tables?
HEAP tables are present in memory and they are used for high speed storage on temporary
• 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
5. What is the default port for MySQL Server?
The default port for MySQL server is 3306.
6. What does myisamchk do?
It compresses the MyISAM tables, which reduces their disk or memory usage.
7. What is BLOB?
BLOB stands for binary large object.
It that can hold a variable amount of data.
There are four types of BLOB based on the maximum length of values they can hold:
8. What is the difference between BLOB and TEXT?
In BLOB sorting and comparison is performed in case-sensitive for BLOB values
In TEXT types sorting and comparison is performed case-insensitive.
9. How is MyISAM table stored?
MyISAM table is stored on disk in three formats.
– ‘.frm’ file – storing the table definition
– ‘.MYD’ (MYData) – data file
– ‘.MYI’ (MYIndex) – index file
10. Explain advantages of MyISAM over InnoDB?
MyISAM follows a much more conservative approach to disk space management – storing each MyISAM table in a separate file, which can be further compresses, if required.
– InnoDB stores the tables in tablespace. Further optimization is difficult with them.