manual.texi 1) earlier change to @xref{} used 2-arg form; change

The extended @strong{MySQL} binary distribution is marked with the

@code{-max} suffix and is configured with the same options as

@code{mysqld-max}. @xref{mysqld-max, @code{mysqld-max}}.

@code{mysqld-max}. @xref{mysqld-max, , @code{mysqld-max}}.

If you want to use the @code{MySQL-Max} RPM, you must first

install the standard @code{MySQL} RPM.

@item

If you see a binary distribution marked with the @code{-max} prefix, this

means that the binary has support for transaction-safe tables and other

features. @xref{mysqld-max, @code{mysqld-max}}.  Note that all binaries

features. @xref{mysqld-max, , @code{mysqld-max}}.  Note that all binaries

are built from the same @strong{MySQL} source distribution.

@item

shell> bin/safe_mysqld --user=mysql &

@end example

@xref{safe_mysqld, @code{safe_mysqld}}.

@xref{safe_mysqld, , @code{safe_mysqld}}.

@xref{Post-installation}.

@strong{MySQL} startup file if you made any changes to it, so you don't lose

your changes.)

After installing the RPM file(s), the @file{mysqld} daemon should be running

After installing the RPM file(s), the @code{mysqld} daemon should be running

and you should now be able to start using @strong{MySQL}.

@xref{Post-installation}.

The following sections indicate some of the issues that have been observed

on particular systems when installing @strong{MySQL} from a binary

distribution.

distribution or from RPM files.

@cindex binary distributions, on Linux

@cindex Linux, binary distribution

signal, you can start @code{mysqld} with the @code{--core-file} option.  Note

that you also probably need to raise the @code{core file size} by adding

@code{ulimit -c 1000000} to @code{safe_mysqld} or starting @code{safe_mysqld}

with @code{--core-file-sizes=1000000}. @xref{safe_mysqld, @code{safe_mysqld}}.

with @code{--core-file-sizes=1000000}. @xref{safe_mysqld, , @code{safe_mysqld}}.

To get a core dump on Linux if @code{mysqld} dies with a SIGSEGV signal, you can 

start @code{mysqld} with the @code{--core-file} option.  Note that you also probably

need to raise the @code{core file size} by adding @code{ulimit -c 1000000} to

@code{safe_mysqld} or starting @code{safe_mysqld} with 

@code{--core-file-sizes=1000000}.  @xref{safe_mysqld, @code{safe_mysqld}}.

@code{--core-file-sizes=1000000}.  @xref{safe_mysqld, , @code{safe_mysqld}}.

If you are linking your own @strong{MySQL} client and get the error:

@code{nohup} causes the command following it to ignore any @code{SIGHUP}

signal sent from the terminal.  Alternatively, start the server by running

@code{safe_mysqld}, which invokes @code{mysqld} using @code{nohup} for you.

@xref{safe_mysqld, @code{safe_mysqld}}.

@xref{safe_mysqld, , @code{safe_mysqld}}.

If you get a problem when compiling mysys/get_opt.c, just remove the

line #define _NO_PROTO from the start of that file!

safe_mysqld or raise the limits for the @code{mysqld} user in /etc/login.conf

(and rebuild it with cap_mkdb /etc/login.conf).  Also be sure you set the

appropriate class for this user in the password file if you are not

using the default (use: chpass mysqld-user-name).  @xref{safe_mysqld,

using the default (use: chpass mysqld-user-name).  @xref{safe_mysqld, ,

@code{safe_mysqld}}.

If you get problems with the current date in @strong{MySQL}, setting the

The above may also happen with a binary @strong{MySQL} distribution if you

don't start @strong{MySQL} by executing exactly @code{./bin/safe_mysqld}!

@xref{safe_mysqld, @code{safe_mysqld}}.

@xref{safe_mysqld, , @code{safe_mysqld}}.

You might need to run @code{mysql_install_db} as @code{root}.  However,

if you prefer, you can run the @strong{MySQL} server as an unprivileged

@item

By invoking @code{safe_mysqld}, which tries to determine the proper options

for @code{mysqld} and then runs it with those options. @xref{safe_mysqld,

for @code{mysqld} and then runs it with those options. @xref{safe_mysqld, ,

@code{safe_mysqld}}.

@item

@item --core-file

Write a core file if @code{mysqld} dies.  For some systems you must also

specify @code{--core-file-size} to @code{safe_mysqld}. @xref{safe_mysqld,

specify @code{--core-file-size} to @code{safe_mysqld}. @xref{safe_mysqld, ,

@code{safe_mysqld}}.

@item -h, --datadir=path

@itemize @bullet

@item

DON'T EVER GIVE ANYONE (EXCEPT THE @strong{MySQL} ROOT USER) ACCESS TO THE

mysql.user TABLE!  The encrypted password is the real password in

@strong{MySQL}. If you know this for one user, you can easily log in as

him if you have access to his 'host'.

@code{user} TABLE IN THE @code{mysql} DATABASE!  The encrypted password

is the real password in @strong{MySQL}. If you know the password listed in

the @code{user} table for a given user, you can easily log in as that

user if you have access to the host listed for that account.

@item

Learn the @strong{MySQL} access privilege system. The @code{GRANT} and

passwords and use them. Instead use @code{MD5()} or another one-way

hashing function.

@item

Do not use passwords from dictionaries. There are special programs to

Do not choose passwords from dictionaries. There are special programs to

break them. Even passwords like ``xfish98'' are very bad.  Much better is

``duag98'' which contains the same word ``fish'' but typed one key to the

left on a standard QWERTY keyboard. Another method is to use ``Mhall'' which

is taken from the first characters of each word in the sentence ``Mary had

a little lamb.'' This is easy to remember and type, but hard to guess for

someone who does not know it.

a little lamb.'' This is easy to remember and type, but difficult to guess

for someone who does not know it.

@item

Invest in a firewall. This protects from at least 50% of all types of

Invest in a firewall. This protects you from at least 50% of all types of

exploits in any software. Put @strong{MySQL} behind the firewall or in

a demilitarized zone (DMZ).

@item

Try to scan your ports from the Internet using a tool such as

@code{nmap}. @strong{MySQL} uses port 3306 by default. This port should

be inaccessible from untrusted hosts. Another simple way to check whether or

not your @strong{MySQL} port is open is to type @code{telnet

server_host 3306} from some remote machine, where

@code{server_host} is the hostname of your @strong{MySQL}

server. If you get a connection and some garbage characters, the port is

be inaccessible from untrusted hosts. Another simple way to check whether

or not your @strong{MySQL} port is open is to try the following command

from some remote machine, where @code{server_host} is the hostname of

your @strong{MySQL} server:

@example

shell> telnet server_host 3306

@end example

If you get a connection and some garbage characters, the port is

open, and should be closed on your firewall or router, unless you really

have a good reason to keep it open. If @code{telnet} just hangs or the

connection is refused, everything is OK; the port is blocked.

with some effort a clever attacker can crack the password if he is able

to sniff the traffic between the client and the server. If the

connection between the client and the server goes through an untrusted

network, you should use an @strong{SSH} tunnel to encrypt the

network, you should use an SSH tunnel to encrypt the

communication.

All other information is transferred as text that can be read by anyone

who is able to watch the connection.  If you are concerned about this,

you can use the compressed protocol (in @strong{MySQL} Version 3.22 and above)

to make things much harder.  To make things even more secure you should use 

@code{ssh}.  You can find an open source ssh client at 

@uref{http://www.openssh.org}, and a commercial ssh client at 

@code{ssh}.  You can find an open source @code{ssh} client at 

@uref{http://www.openssh.org}, and a commercial @code{ssh} client at 

@uref{http://www.ssh.com}.  With this, you can get an encrypted TCP/IP 

connection between a @strong{MySQL} server and a @strong{MySQL} client.

@end example

@item

Don't run the @strong{MySQL} daemon as the Unix @code{root} user.

It is very dangerous as any user with @code{FILE} privileges will be able to

create files

as @code{root} (for example, @code{~root/.bashrc}). To prevent this

@code{mysqld} will refuse to run as @code{root} unless it is specified

directly via @code{--user=root} option.

Don't run the @strong{MySQL} daemon as the Unix @code{root} user.  This is

very dangerous, because any user with @code{FILE} privileges will be able

to create files as @code{root} (for example, @code{~root/.bashrc}). To

prevent this, @code{mysqld} will refuse to run as @code{root} unless it

is specified directly using a @code{--user=root} option.

@code{mysqld} can be run as an ordinary unprivileged user instead.

You can also create a new Unix user @code{mysql} to make everything

even more secure.  If you run @code{mysqld} as another Unix user,

you don't need to change the @code{root} user name in the @code{user}

table, because @strong{MySQL} user names have nothing to do with Unix

user names.  To start @code{mysqld} as another Unix user, add a @code{user}

line that specifies the user name to the @code{[mysqld]} group of the

@file{/etc/my.cnf} option file or the @file{my.cnf} option file in the

server's data directory. For example:

@example

[mysqld]

user=mysql

@end example

@code{mysqld} can be run as any user instead.  You can also create a new

Unix user @code{mysql} to make everything even more secure.  If you run

@code{mysqld} as another Unix user, you don't need to change the

@code{root} user name in the @code{user} table, because @strong{MySQL}

user names have nothing to do with Unix user names.  You can edit the

@code{mysql.server} script to start @code{mysqld} as another Unix user.

Normally this is done with the @code{su} command.  For more details, see

@ref{Changing MySQL user, , Changing @strong{MySQL} user}.

This will cause the server to start as the designated user whether you

start it manually or by using @code{safe_mysqld} or @code{mysql.server}.

For more details, see @ref{Changing MySQL user, , Changing @strong{MySQL}

user}.

@item

Don't support symlinks to tables (This can be disabled with the

directories could then delete any file in the system!

@xref{Symbolic links to tables}.

@item

If you put a password for the Unix @code{root} user in the @code{mysql.server}

script, make sure this script is readable only by @code{root}.

@item

Check that the Unix user that @code{mysqld} runs as is the only user with

read/write privileges in the database directories.

@item

On Unix platforms, do not run @code{mysqld} as root unless you really

need to. Consider creating a user named @code{mysql} for that purpose.

@item

Don't give the @strong{process} privilege to all users.  The output of

@code{mysqladmin processlist} shows the text of the currently executing

If you have downloaded a binary version of @strong{MySQL} that includes

support for BerkeleyDB, simply follow the instructions for installing a 

binary version of @strong{MySQL}.  

@xref{Installing binary}.  @xref{mysqld-max, @code{mysqld-max}}.

@xref{Installing binary}.  @xref{mysqld-max, , @code{mysqld-max}}.

To compile @strong{MySQL} with Berkeley DB support, download @strong{MySQL}

Version 3.23.34 or newer and configure @code{MySQL} with the 

If you have downloaded a binary version of @strong{MySQL} that includes

support for InnoDB (mysqld-max), simply follow the instructions for

installing a binary version of @strong{MySQL}. @xref{Installing binary}.

@xref{mysqld-max, @code{mysqld-max}}.

@xref{mysqld-max, , @code{mysqld-max}}.

To compile @strong{MySQL} with InnoDB support, download MySQL-3.23.37 or newer

and configure @code{MySQL} with the @code{--with-innodb} option.

another @code{mysqld} binary in an existing installation.  Just

run @code{configure} with the options you want and then install the

new @code{mysqld} binary as @code{mysqld-max} in the same directory

where your old @code{mysqld} binary is. @xref{safe_mysqld, @code{safe_mysqld}}.

where your old @code{mysqld} binary is. @xref{safe_mysqld, , @code{safe_mysqld}}.

The @code{mysqld-max} RPM uses the above mentioned @code{safe_mysqld}

feature. It just installs the @code{mysqld-max} executable and

release) if test -d /data/mysql -a -f ./share/mysql/english/errmsg.sys

-a -x ./bin/mysqld

--------------------------------------------------------------------------

@xref{safe_mysqld, @code{safe_mysqld}}.

@xref{safe_mysqld, , @code{safe_mysqld}}.

@end example

The above test should be successful, or you may encounter problems.

@item

and/or populate the table.

If you are doing a backup on the server, you should consider using

the @code{mysqlhotcopy} instead. @xref{mysqlhotcopy, @code{mysqlhotcopy}}.

the @code{mysqlhotcopy} instead. @xref{mysqlhotcopy, , @code{mysqlhotcopy}}.

@example

shell> mysqldump [OPTIONS] database [tables]

to run as the Unix user @code{user_name} before accepting any connections.

@item

If you are using the @code{mysql.server} script to start @code{mysqld} when

the system is rebooted, you should edit @code{mysql.server} to use @code{su}

to run @code{mysqld} as user @code{user_name}, or to invoke @code{mysqld}

with the @code{--user} option.  (No changes to @code{safe_mysqld} are

necessary.)

To start the server as the given user name automatically at system

startup time, add a @code{user} line that specifies the user name to

the @code{[mysqld]} group of the @file{/etc/my.cnf} option file or the

@file{my.cnf} option file in the server's data directory. For example:

@example

[mysqld]

user=user_name

@end example

@end enumerate

At this point, your @code{mysqld} process should be running fine and dandy as

TABLE}. @xref{SELECT}. @xref{BACKUP TABLE}.

Another way to back up a database is to use the @code{mysqldump} program or

the @code{mysqlhotcopy script}. @xref{mysqldump, @code{mysqldump}}.

@xref{mysqlhotcopy, @code{mysqlhotcopy}}.

the @code{mysqlhotcopy script}. @xref{mysqldump, , @code{mysqldump}}.

@xref{mysqlhotcopy, , @code{mysqlhotcopy}}.

@enumerate

@item

If you want to run multiple servers, the easiest way is to compile the servers

with different TCP/IP ports and socket files so they are not

both listening to the same TCP/IP port or socket file. @xref{mysqld_multi}.

both listening to the same TCP/IP port or socket file. @xref{mysqld_multi, ,

@code{mysqld_multi}}.

Assume an existing server is configured for the default port number and

socket file.  Then configure the new server with a @code{configure} command

If you want to know if the query should return a result set or not, you can

use @code{mysql_field_count()} to check for this.

@xref{mysql_field_count, @code{mysql_field_count}}.

@xref{mysql_field_count, , @code{mysql_field_count}}.

@subsubheading Return Values

@item

@code{SHOW KEYS} now shows whether or not key is @code{FULLTEXT}.

@item

New script @file{mysqld_multi}. @xref{mysqld_multi}.

New script @file{mysqld_multi}. @xref{mysqld_multi, , @code{mysqld_multi}}.

@item

Added new script, @file{mysql-multi.server.sh}.  Thanks to

Tim Bunce @email{Tim.Bunce@@ig.co.uk} for modifying @file{mysql.server} to

Added new options @code{--pager[=...]}, @code{--no-pager},

@code{--tee=...} and @code{--no-tee} to the @code{mysql} client.  The

new corresponding interactive commands are @code{pager}, @code{nopager},

@code{tee} and @code{notee}. @xref{mysql, @code{mysql}}, @code{mysql --help}

@code{tee} and @code{notee}. @xref{mysql, , @code{mysql}}, @code{mysql --help}

and the interactive help for more information.

@item

Fixed crash when automatic repair of @code{MyISAM} table failed.