What
Is MySQL?
MySQL is an Oracle backed open source relational database management system.
Its name is combinations of “My”, the name of co-founder Michael
Widenius's daughter, and "SQL",
the abbreviation for Structured Query Language.
MySQL was created by a Swedish company, MySQL AB,
founded by David Axmark, Allan Larsson and Michael and the first internal release was on 23 May 1995.
MySQL is an important component of an open source
enterprise stack called LAMP.
MySQL runs on virtually all platforms, including Linux, UNIX, and Windows.
MySQL can also be run on cloud computing platforms
such as Microsoft Azure, Amazon EC2, and Oracle Cloud Infrastructure.
Now MySQL Server 8.0 was announced in April 2018.
MySQL
Server 8.0 contains the following -
1. NoSQL
Document Store
2. Atomic
and crash safe DDL sentences
3. JSON
Extended syntax
4. Introduce
New Functions - JSON table functions, improved sorting, and partial updates
How
MySQL Works?
MySQL is based on a client-server model.
MySQL server is available as a separate program
for use in a client server networked environment and as a library that can be linked
into separate applications.
What
Are the Features of MySQL?
1. MySQL
provides cross-platform support.
2. Different
backend
3. Multithreaded
SQL server supporting various client programs and libraries
4. MySQL
has many stored procedures like triggers and cursors that helps in managing the
database
5. Administrative
tools
What
Is Default Port Number of MySQL?
The default port number for MySQL Server is 3306
and the TCP/IP standard default port is 1433 in for SQL Server.
What
Is the Maximum Length of a Table name, Database name, and Fieldname in MySQL?
The following table describes the maximum length
for each type of identifier which is -
1. Database
64 bytes
2. Table
64 bytes
3. Column
64 bytes
4. Index
64 bytes
5. Alias
255 bytes
Is
there an Object Oriented Version of MySQL library functions?
MySQLi is an object oriented version of MySQL and
it interfaces in PHP.
What
Are the Limitations of MySQL?
The
Limitations of Joins -
The maximum number of tables that can be
referenced in a single join is 61.
Limitations
of Innodb Storage Engine -
1. A
table cannot contain more than 1000 columns.
2. The
maximum number of columns per index is 16.
3. The
maximum table space size is 4 Mia database pages (64 Tbyte).
Limitations
of the MyISAM Storage Engine -
1. Large
files up to 63-bit file length are supported.
2. There
is a limitation of 264 rows in a MyISAM table.
3. The
maximum key length is 1000 bytes.
Limitations
of MySQL CLUSTER -
1. Max
attributes/columns in an index are 32.
2. Max
number of attributes (columns and indexes) in a table is 128.
3. Max
number of table is 1792.
4. Max
size in bytes of a row is 8052 byte, excluding blobs which are stored
separately.
5. Max
number of nodes in a cluster is 255 in CGE.
6. Max
number of metadata objects is 20320.
7. Max
attribute name length is 31 characters.
8. Max
database + table name length is 122 characters.
The
Advantages of Using MySQL -
1. MySQL
is Open-Source, free, fast, reliable, and relational database.
2. MySQL
is Easy To Use
3. MySQL
uses only just under 1 MB of RAM on your laptop while Oracle 9i installation
uses 128 MB.
4. MySQL
is Incredibly Inexpensive
5. MySQL
is an Industry Standard
What
Are The Disadvantages Of Using MySQL?
The
Disadvantages of Using MySQL -
1. Some
Stability Issues - MySQL is not so efficient for large scale databases.
2. Poor
Performance
3. Transactions
are not handled very efficiently
4. Developers
have some Of Limitations as like Joins, CLUSTER, and Inodb storage engine.
What
Is mysqlcheck do?
The mysqlcheck
is a client program which used to check the integrity of database tables.
What
Is mysqldump?
The mysqldump
is a client program which used to create logical backups of database.
In
which language MySQL Is Written?
The MySQL is written in C and C++ and The SQL
parser is written in yacc.
How
Do You Change a Password for an Existing user via mysqladmin?
The mysqladmin -u root -p password
“Your-new-password”
What
Are the Different Types of Tables in MySQL?
There are three different types of tables in
MySQL -
1. HEAP
2. InoDB
3. BDB
What
Is BLOB in MySQL?
The BLOB
is an acronym stands for a large binary object and its used to hold a variable
amount of data.
There are 4 Types of BLOB -
1. BLOB
2. TINYBLOB
3. MEDIUMBLOB
4. LONGBLOB
What
Is TEXT in MySQL?
The TEXT
is a case-insensitive BLOB and the TEXT values are non-binary strings
(character string).
There are 4 Types of TEXT -
1. TEXT
2. TINYTEXT
3. MEDIUMTEXT
4. LONGTEXT
What
Are HEAP Tables?
The HEAP tables are in-memory and used for high
speed temporary storages.
The HEAP tables do not support AUTO INCREMENT, TEXT,
and BLOB fields.
What
Does Tee Command do in MySQL?
The “tee”
followed by a filename turns on MySQL logging to a specified file.
What
Are Advantages of InnoDB over MyISAM?
The Advantages of InnoDB over MyISAM are -
1. Row
Level Locking
2. Transactions
3. Foreign
Key Constraints
4. Crash
Recovery
How
To Get the Current SQL version?
The SELECT
VERSION (); query is used for get the current SQL version.
How
To Get the Current Date in MySQL?
The SELECT
CURRENT_DATE(); query is used for get the current date in MySQL.
What
Is a Trigger in MySQL?
A trigger is a set of codes that executes in
response to some events.
How
To Resolve the Problem of Data Disk that is Full?
When the data disk is full and overloaded the way
out is to create and soft link and move the .frm as well as the .idb files into
that link location.
What
Is the Difference Between mysql_fetch_array and mysql_fetch_object?
The mysql_fetch_array()
is used to returns a result row as an
associated array.
Teh mysql_fetch_object()
is used to returns a result row as
object from database.
How
Many Triggers Are Possible in MySQL?
There Are Only Six Triggers allowed using in
MySQL database i.e.
1. Before
Insert
2. After
Insert
3. Before
Update
4. After
Update
5. Before
Delete
6. After
Delete
I hope You Enjoyed. Thank you Very Much for your
Time.