MySQL : Introduction to MySQL
Birth Of MySQL
MySQL started out with the intention of using the mSQL database system to connect to tables using fast low-level (ISAM) routines. However, after some testing, They conclude that mSQL was not fast enough or flexible enough. This resulted in a new SQL interface to our database but with almost the same API interface as mSQL. This API was designed to enable third-party code that was written for use with mSQL to be ported easily for use with MySQL
Its Named to MySQL
MySQL is named after co-founder Monty Widenius’s daughter, My.
MySQL Logo
The name of the MySQL Dolphin (MySQL logo) is “Sakila”, which was chosen from a huge list of names suggested by users in our “Name the Dolphin” contest. The winning name was submitted by Ambrose Twebaze, an Open Source software developer from Swaziland, Africa. According to Ambrose, the feminine name Sakila has its roots in SiSwati, the local language of Swaziland. Sakila is also the name of a town in Arusha, Tanzania, near Ambrose’s country of origin, Uganda.
The Main Feature of MySQL
We will describe some of the important characteristics of the MySQL Database Software. In most respects, the roadmap applies to all versions of MySQL.
Internals and Portability
- Written in C and C++.
- Tested with a broad range of different compilers.
- Works on many different platforms
- For portability, uses CMake in MySQL 5.5 and up. Previous series use GNU Automake, Autoconf, and Libtool.
- Tested with Purify (a commercial memory leakage detector) as well as with Valgrind, a GPL tool.
- Uses multi-layered server design with independent modules.
- Designed to be fully multi-threaded using kernel threads, to easily use multiple CPUs if they are available.
- Provides transactional and nontransactional storage engines.
- Uses very fast B-tree disk tables (MyISAM) with index compression.
- Designed to make it relatively easy to add other storage engines. This is useful if you want to provide an SQL interface for an in-house database.
- Uses a very fast thread-based memory allocation system.
- Executes very fast joins using an optimized nested-loop join.
- Implements in-memory hash tables, which are used as temporary tables.
- Implements SQL functions using a highly optimized class library that should be as fast as possible. Usually there is no memory allocation at all after query initialization.
- Provides the server as a separate program for use in a client/server networked environment, and as a library that can be embedded (linked) into standalone applications. Such applications can be used in isolation or in environments where no network is available.
Data Types
- Many data types: signed/unsigned integers 1, 2, 3, 4, and 8 bytes long, FLOAT, DOUBLE, CHAR, VARCHAR, BINARY, VARBINARY, TEXT, BLOB, DATE, TIME, DATETIME, TIMESTAMP, YEAR, SET, ENUM, and OpenGIS spatial types.
- Fixed-length and variable-length string types.
Statements and Functions
- Full operator and function support in the SELECT list and WHERE clause of queries.
- Full support for SQL GROUP BY and ORDER BY clauses. Support for group functions (COUNT(), AVG(), STD(), SUM(), MAX(), MIN(), and GROUP_CONCAT()).
- Support for LEFT OUTER JOIN and RIGHT OUTER JOIN with both standard SQL and ODBC syntax.
- Support for aliases on tables and columns as required by standard SQL.
- Support for DELETE, INSERT, REPLACE, and UPDATE to return the number of rows that were changed or to return the number of rows matched instead by setting a flag when connecting to the server.
- Support for MySQL-specific SHOW statements that retrieve information about databases, storage engines, tables, and indexes. Support for the INFORMATION_SCHEMA database, implemented according to standard SQL.
- An EXPLAIN statement to show how the optimizer resolves a query.
- Independence of function names from table or column names. For example, ABS is a valid column name. The only restriction is that for a function call, no spaces are permitted between the function name and the “(” that follows it.
- You can refer to tables from different databases in the same statement.
Security
- A privilege and password system that is very flexible and secure, and that enables host-based verification.
- Password security by encryption of all password traffic when you connect to a server.
Scalability and Limits
- Support for large databases. We use MySQL Server with databases that contain 50 million records, even more than this.
- Support for up to 64 indexes per table. Each index may consist of 1 to 16 columns or parts of columns.
- The maximum index width for InnoDB tables is either 767 bytes or 3072 bytes.
- The maximum index width for MyISAM tables is 1000 bytes.
- An index may use a prefix of a column for CHAR, VARCHAR, BLOB, or TEXT column types.
Connectivity
- Clients can connect to MySQL Server using several protocols:
- Clients can connect using TCP/IP sockets on any platform.
- On Windows systems, clients can connect using named pipes if the server is started with the — enable-named-pipe option. Windows servers also support shared-memory connections if started with the –shared-memory option. Clients can connect through shared memory by using the — protocol=memory option.
- On Unix systems, clients can connect using Unix domain socket files.
- MySQL client programs can be written in many languages. A client library written in C is available for clients written in C or C++, or for any language that provides C bindings.
- APIs for C, C++, Eiffel, Java, Perl, PHP, Python, Ruby, and Tcl are available, enabling MySQL clients to be written in many languages
- The Connector/ODBC (MyODBC) interface provides MySQL support for client programs that use ODBC (Open Database Connectivity) connections. For example, you can use MS Access to connect to your MySQL server. Clients can be run on Windows or Unix. Connector/ODBC source is available. All ODBC 2.5 functions are supported, as are many others.
- The Connector/J interface provides MySQL support for Java client programs that use JDBC connections. Clients can be run on Windows or Unix. Connector/J source is available.
- MySQL Connector/Net enables developers to easily create .NET applications that require secure, high-performance data connectivity with MySQL. It implements the required ADO.NET interfaces and integrates into ADO.NET aware tools. Developers can build applications using their choice of .NET languages. MySQL Connector/Net is a fully managed ADO.NET driver written in 100% pure C#.
Clients and Tools
- MySQL includes several client and utility programs. These include both command-line programs such as mysqldump and mysqladmin, and graphical programs such as MySQL Workbench and may other tools.
- MySQL Server has built-in support for SQL statements to check, optimize, and repair tables. These statements are available from the command line through the mysqlcheck client. MySQL also includes myisamchk, a very fast command-line utility for performing these operations on MyISAM tables.
- MySQL programs can be invoked with the –help or -? option to obtain online assistance.
