Quick rearrange and ordering of "main features" list.

@c This list is too technical and should be divided into one feature

@c list comparable to commercial competition and a very technical on

@c with max limits (from crash-me) and so on.

@itemize @asis

@item

Internals and portability

@itemize @bullet

@item

Written in C and C++.  Tested with a broad range of different compilers.

@item

No memory leaks.  MySQL has been tested with Purify, a commercial

memory leakage detector.

@item

Works on many different platforms.  @xref{Which OS}.

@item

Uses GNU Automake, Autoconf, and Libtool for portability.

@item

APIs for C, C++, Eiffel, Java, Perl, PHP, Python and Tcl.  @xref{Clients}.

@item

Fully multi-threaded using kernel threads.  This means it can easily

use multiple CPUs if available.

@item

C, C++, Eiffel, Java, Perl, PHP, Python and Tcl APIs.  @xref{Clients}.

Very fast B-tree disk tables with index compression.

@item

Works on many different platforms.  @xref{Which OS}.

A very fast thread-based memory allocation system.

@item

Very fast joins using an optimized one-sweep multi-join.

@item

In-memory hash tables which are used as temporary tables.

@item

SQL functions are implemented through a highly optimized class library and

should be as fast as possible!  Usually there isn't any memory allocation 

at all after query initialization.

@end itemize

@item

Column types

@itemize @bullet

@item

Many column types: signed/unsigned integers 1, 2, 3, 4, and 8 bytes

long, @code{FLOAT}, @code{DOUBLE}, @code{CHAR}, @code{VARCHAR},

@code{TEXT}, @code{BLOB}, @code{DATE}, @code{TIME}, @code{DATETIME},

@code{TIMESTAMP}, @code{YEAR}, @code{SET}, and @code{ENUM} types. 

@xref{Column types}.

@item

Very fast joins using an optimized one-sweep multi-join.

Fixed-length and variable-length records.

@item

@cindex default values

All columns have default values.

You can use @code{INSERT} to insert a subset of a table's columns; those

columns that are not explicitly given values are set to their default

values.

@end itemize

@item

Commands and functions

@itemize @bullet

@item

Full operator and function support in the @code{SELECT} and @code{WHERE}

parts of queries.  For example:

@example

mysql> SELECT CONCAT(first_name, " ", last_name) FROM tbl_name

           WHERE income/dependents > 10000 AND age > 30;

@end example

@item

SQL functions are implemented through a highly optimized class library and

should be as fast as possible!  Usually there isn't any memory allocation 

at all after query initialization.

@item

Full support for SQL @code{GROUP BY} and @code{ORDER BY} clauses.  Support 

for group functions (@code{COUNT()}, @code{COUNT(DISTINCT ...)}, 

@code{AVG()}, @code{STD()}, @code{SUM()}, @code{MAX()} and @code{MIN()}).

@item

Support for @code{LEFT OUTER JOIN} and @code{RIGHT OUTER JOIN} with ANSI

SQL and ODBC syntax.

@item

Aliases on tables and columns are allowed as in the SQL92 standard.

@item

@code{DELETE}, @code{INSERT}, @code{REPLACE}, and @code{UPDATE} return

the number of rows that were changed (affected).  It is possible to return

the number of rows matched instead by setting a flag when connecting to the

server.

@item

The MySQL-specific @code{SHOW} command can be used to retrieve

information about databases, tables, and indexes.  The @code{EXPLAIN} command

can be used to determine how the optimizer resolves a query.

@item

Function names do not clash with table or column names.  For example, 

@code{ABS} is a valid column name.  The only restriction is that for a 

function call, no spaces are allowed between the function name and the 

@samp{(} that follows it.  @xref{Reserved words}.

@item

You can mix tables from different databases in the same query (as of

Version 3.22).

@end itemize

@item

Security

@itemize @bullet

@item

A privilege and password system that is very flexible and secure, and

allows host-based verification.  Passwords are secure because all

password traffic is encrypted when you connect to a server.

@end itemize

@item

ODBC (Open-DataBase-Connectivity) support for Win32 (with source).  All

ODBC 2.5 functions and many others.  For example, you can use MS Access to

connect to your MySQL server.  @xref{ODBC}.

@itemize @bullet

Scalability and limits

@item

Very fast B-tree disk tables with index compression.

Handles large databases.  We are using MySQL with some

databases that contain 50,000,000 records and we know of users that

uses MySQL with 60,000 tables and about 5,000,000,000 rows.

@item

Up to 32 indexes per table are allowed.  Each index may consist of 1 to 16

columns or parts of columns.  The maximum index width is 500 bytes

(this may be changed when compiling MySQL).  An index may use a prefix

of a @code{CHAR} or @code{VARCHAR} field.

@end itemize

@item

Fixed-length and variable-length records.

@item

In-memory hash tables which are used as temporary tables.

Clients and tools

@izemize @bullet

@item

Handles large databases.  We are using MySQL with some

databases that contain 50,000,000 records and we know of users that

uses MySQL with 60,000 tables and about 5,000,000,000 rows

Includes @code{myisamchk}, a very fast utility for table checking,

optimization, and repair.  All of the functionality of @code{myisamchk}

is also available through the SQL interface as well.  

@xref{MySQL Database Administration}.

@item

@cindex default values

All columns have default values.

You can use @code{INSERT} to insert a subset of a table's columns; those

columns that are not explicitly given values are set to their default

values.

All MySQL programs can be invoked with the @code{--help} or @code{-?}

options to obtain online assistance.

@end itemize

@item

Uses GNU Automake, Autoconf, and Libtool for portability.

Connectivity

@itemize @bullet

@item

Written in C and C++.  Tested with a broad range of different compilers.

ODBC (Open-DataBase-Connectivity) support for Win32 (with source).  All

ODBC 2.5 functions and many others.  For example, you can use MS Access to

connect to your MySQL server.  @xref{ODBC}.

@item

A very fast thread-based memory allocation system.

Clients may connect to the MySQL server using TCP/IP Sockets,

Unix Sockets (Unix), or Named Pipes (NT).

@end itemize

@item

No memory leaks.  MySQL has been tested with Purify, a commercial

memory leakage detector.

Localization

@itemize @bullet

@item

Includes @code{myisamchk}, a very fast utility for table checking,

optimization, and repair.  All of the functionality of @code{myisamchk}

is also available through the SQL interface as well.  

@xref{MySQL Database Administration}.

The server can provide error messages to clients in many languages. 

@xref{Languages}.

@item

Full support for several different character sets, including

ISO-8859-1 (Latin1), german, big5, ujis, and more.  For example, the

Scandinavian characters `@ringaccent{a}', `@"a' and `@"o' are allowed

in table and column names.

@item

All data are saved in the chosen character set.  All comparisons for normal

All data is saved in the chosen character set.  All comparisons for normal

string columns are case insensitive.

@item

Sorting is done according to the chosen character set (the Swedish

way by default).  It is possible to change this when the MySQL server

is started up.  To see an example of very advanced sorting, look at the

Czech sorting code.  MySQL supports many different character sets

that can be specified at compile and run time.

@end itemize

@item

Aliases on tables and columns are allowed as in the SQL92 standard.

@item

@code{DELETE}, @code{INSERT}, @code{REPLACE}, and @code{UPDATE} return

the number of rows that were changed (affected).  It is possible to return

the number of rows matched instead by setting a flag when connecting to the

server.

@item

Function names do not clash with table or column names.  For example, 

@code{ABS} is a valid column name.  The only restriction is that for a 

function call, no spaces are allowed between the function name and the 

@samp{(} that follows it.  @xref{Reserved words}.

@item

All MySQL programs can be invoked with the @code{--help} or @code{-?}

options to obtain online assistance.

@item

The server can provide error messages to clients in many languages. 

@xref{Languages}.

@item

Clients may connect to the MySQL server using TCP/IP Sockets,

Unix Sockets (Unix), or Named Pipes (NT).

@item

The MySQL-specific @code{SHOW} command can be used to retrieve

information about databases, tables, and indexes.  The @code{EXPLAIN} command

can be used to determine how the optimizer resolves a query.

@end itemize