Oracle 5.0, Справочное руководство

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The Main Features of MySQL
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The official way to pronounce “MySQL” is “My Ess Que Ell” (not “my sequel”), but we do not mind if you
pronounce it as “my sequel” or in some other localized way.
1.3.2. The Main Features of MySQL
This section describes some of the important characteristics of the MySQL Database Software. See
also
Section 1.5, “MySQL Development History” . In most respects, the roadmap applies to all versions
of MySQL. For information about features as they are introduced into MySQL on a series-specific
basis, see the “In a Nutshell” section of the appropriate Manual:
• MySQL 5.6: MySQL 5.6 in a Nutshell
• MySQL 5.5: MySQL 5.5 in a Nutshell
• MySQL 5.1: MySQL 5.1 in a Nutshell
• MySQL 5.0: MySQL 5.0 in a Nutshell
Internals and Portability:
• Written in C and C++.
• Tested with a broad range of different compilers.
• Works on many different platforms. See Section 2.4.2, “Operating Systems Supported by MySQL
Community Server” .
• 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
( http://developer.kde.org/~sewardj/ ).
• 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. See Chapter 11, Data Types .
• Fixed-length and variable-length string types.