学步园

 

Server Command Options

When you start the mysqld server, you can specify program options
using any of the methods described in Section 4.2.3, “Specifying Program
Options”. The most common methods are to provide options in an option file
or on the command line. However, in most cases it is desirable to make sure that
the server uses the same options each time it runs. The best way to ensure this
is to list them in an option file. See Section 4.2.3.2, “Using Option Files”.

MySQL Enterprise.  For expert advice on setting command
options, subscribe to the MySQL Enterprise Monitor. For more information, see http://www.mysql.com/products/enterprise/advisors.html.

mysqld reads options from the [mysqld] and [server] groups. mysqld_safe reads options from the [mysqld], [server], [mysqld_safe], and [safe_mysqld]
groups. mysql.server reads options from the [mysqld] and [mysql.server]
groups.

An embedded MySQL server usually reads options from the [server], [embedded], and [xxxxx_SERVER]
groups, where xxxxx is the name of the
application into which the server is embedded.

mysqld accepts many command options. For a
brief summary, execute mysqld
--help. To see the full list, use mysqld --verbose
--help.

The following list shows some of the most common server options. Additional
options are described in other sections:

• Options that affect security: See Section 5.3.3, “Security-Related
  mysqld Options”.

• SSL-related options: See Section 5.5.7.3, “SSL Command Options”.

• Binary log control options: See Section 5.2.4, “The Binary Log”.

• Replication-related options: See Section 16.1.3, “Replication and Binary
  Logging Options and Variables”.

• Options specific to particular storage engines: See Section 13.5.1, “MyISAM Startup Options”, Section 13.6.3, “InnoDB Startup Options and System Variables”, and Section 17.4.2,
  “mysqld Command Options for MySQL
  Cluster”.

You can also set the values of server system variables by using variable
names as options, as described at the end of this section.

• --help, -?

  Command Line Format	-?
  Config File Format	help

  Display a short help message and exit. Use both the --verbose
  and --help
  options to see the full message.

• --allow-suspicious-udfs

  Command Line Format

  --allow-suspicious-udfs

  Config File Format

  allow-suspicious-udfs

  Value Set

  Type	boolean
  Default	FALSE

  This option controls whether user-defined functions that have only an xxx symbol for the main function can be loaded. By default,
  the option is off and only UDFs that have at least one auxiliary symbol can be
  loaded; this prevents attempts at loading functions from shared object files
  other than those containing legitimate UDFs. See Section 22.3.2.6, “User-Defined Function
  Security Precautions”.

• --ansi

  Command Line Format	--ansi
  Config File Format	ansi

  Use standard (ANSI) SQL syntax instead of MySQL syntax. For more precise
  control over the server SQL mode, use the --sql-mode
  option instead. See Section 1.7.3, “Running MySQL in ANSI Mode”,
  and Section 5.1.7, “Server SQL Modes”.

• --basedir=path,
  -b path

  Command Line Format

  --basedir=name

  Config File Format

  basedir

  Option Sets Variable

  Yes, basedir

  Variable Name

  basedir

  Variable Scope

  Global

  Dynamic Variable

  No

  Value Set

  Type

  filename

  The path to the MySQL installation directory. All paths are usually resolved
  relative to this directory.

• --big-tables

  Command Line Format

  --big-tables

  Config File Format

  big-tables

  Option Sets Variable

  Yes, big_tables

  Variable Name

  big-tables

  Variable Scope

  Session

  Dynamic Variable

  Yes

  Value Set

  Type

  boolean

  Allow large result sets by saving all temporary sets in files. This option
  prevents most “table full” errors, but also slows down
  queries for which in-memory tables would suffice. Since MySQL 3.23.2, the server
  is able to handle large result sets automatically by using memory for small
  temporary tables and switching to disk tables where necessary.

• --bind-address=IP

  Command Line Format

  --bind-address=name

  Config File Format

  bind-address

  Value Set

  Type	string
  Default	0.0.0.0
  Range	0.0.0.0-255.255.255.255

  The IP address to bind to. Only one address can be selected. If this option
  is specified multiple times, the last address given is used.

  If no address or 0.0.0.0 is specified, the server
  listens on all interfaces.

• --binlog-format={ROW|STATEMENT|MIXED}

  Version Introduced

  5.1.5

  Command Line Format

  --binlog-format

  Config File Format

  binlog-format

  Option Sets Variable

  Yes, binlog_format

  Variable Name

  binlog_format

  Variable Scope

  Both

  Dynamic Variable

  Yes

  Value Set (>= 5.1.5, <=
  5.1.7)

  Type	enumeration
  Default	STATEMENT
  Valid Values	ROW, STATEMENT

  Value Set (>= 5.1.8, <=
  5.1.11)

  Type	enumeration
  Default	STATEMENT
  Valid Values	ROW, STATEMENT, MIXED

  Value Set (>= 5.1.12, <=
  5.1.28)

  Type	enumeration
  Default	MIXED
  Valid Values	ROW, STATEMENT, MIXED

  Value Set (>= 5.1.29)

  Type	enumeration
  Default	STATEMENT
  Valid Values	ROW, STATEMENT, MIXED

  Specify whether to use row-based, statement-based, or mixed replication
  (statement-based was the default prior to MySQL 5.1.12; in 5.1.12, the default
  was changed to mixed replication; in 5.1.29, the default was changed back to
  statement-based). See Section 16.1.2, “Replication Formats”.
  This option was added in MySQL 5.1.5.

  Important

  MySQL Cluster.  The default value for this option in all MySQL Cluster
  NDB 6.1, 6.2, 6.3, and later 6.x releases is MIXED.
  See Section 17.9.2, “MySQL
  Cluster Replication — Assumptions and General Requirements”, for more
  information.

• --bootstrap

  Command Line Format	--bootstrap
  Config File Format	bootstrap

  This option is used by the mysql_install_db script to create the MySQL
  privilege tables without having to start a full MySQL server.

  This option is unavailable if MySQL was configured with the --disable-grant-options option. See Section 2.10.2, “Typical configure Options”.

• --character-sets-dir=path

  Command Line Format

  --character-sets-dir=name

  Config File Format

  character-sets-dir

  Option Sets Variable

  Yes, character_sets_dir

  Variable Name

  character-sets-dir

  Variable Scope

  Global

  Dynamic Variable

  No

  Value Set

  Type

  filename

  The directory where character sets are installed. See Section 9.2, “The Character Set Used for Data and
  Sorting”.

• --character-set-client-handshake

  Command Line Format

  --character-set-client-handshake

  Config File Format

  character-set-client-handshake

  Value Set

  Type	boolean
  Default	TRUE

  Don't ignore character set information sent by the client. To ignore client
  information and use the default server character set, use --skip-character-set-client-handshake; this makes MySQL
  behave like MySQL 4.0.

• --character-set-filesystem=charset_name

  Version Introduced

  5.1.6

  Command Line Format

  --character-set-filesystem=name

  Config File Format

  character-set-filesystem

  Option Sets Variable

  Yes, character_set_filesystem

  Variable Name

  character_set_filesystem

  Variable Scope

  Both

  Dynamic Variable

  Yes

  Value Set

  Type

  string

  The file system character set. This option sets the character_set_filesystem system variable. It was added
  in MySQL 5.1.6.

• --character-set-server=charset_name, -C charset_name

  Command Line Format

  --character-set-server

  Config File Format

  character-set-server

  Option Sets Variable

  Yes, character_set_server

  Variable Name

  character_set_server

  Variable Scope

  Both

  Dynamic Variable

  Yes

  Value Set

  Type

  string

  Use charset_name as the default
  server character set. See Section 9.2, “The Character Set Used for Data and
  Sorting”. If you use this option to specify a non-default character set, you
  should also use --collation-server to specify the collation.

• --chroot=path, -r path

  Command Line Format

  --chroot=name

  Config File Format

  chroot

  Value Set

  Type

  filename

  Put the mysqld server in a closed environment during
  startup by using the chroot() system call. This is a
  recommended security measure. Note that use of this option somewhat limits LOAD DATA INFILE
  and SELECT ... INTO OUTFILE.

• --collation-server=collation_name

  Command Line Format

  --collation-server

  Config File Format

  collation-server

  Option Sets Variable

  Yes, collation_server

  Variable Name

  collation_server

  Variable Scope

  Both

  Dynamic Variable

  Yes

  Value Set

  Type

  string

  Use collation_name as the default
  server collation. See Section 9.2, “The Character Set Used for Data and
  Sorting”.

• --console

  Command Line Format	--console
  Config File Format	console
  Platform Specific	windows

  (Windows only.) Write error log messages to stderr
  and stdout even if --log-error is specified. mysqld does not close the console window if
  this option is used.

• --core-file

  Command Line Format

  --core-file

  Config File Format

  core-file

  Value Set

  Type	boolean
  Default	TRUE

  Write a core file if mysqld dies. The name and location of the core
  file is system dependent. On Linux, a core file named core.pid is
  written to the current working directory of the process, which for mysqld is the data directory. pid represents the process ID of the server
  process. On Mac OS X, a core file named core.pid is written to the /cores directory. On Solaris, use the coreadm command to specify where to write the core
  file and how to name it.

  For some systems, to get a core file you must also specify the --core-file-size option to mysqld_safe. See Section 4.3.2, “mysqld_safe — MySQL Server Startup Script”. On
  some systems, such as Solaris, you do not get a core file if you are also using
  the --user
  option. There might be additional restrictions or limitations. For example, it
  might be necessary to execute ulimit -c
  unlimited before starting the server. Consult your system
  documentation.

• --datadir=path,
  -h path

  Command Line Format

  --datadir=name

  Config File Format

  datadir

  Option Sets Variable

  Yes, datadir

  Variable Name

  datadir

  Variable Scope

  Global

  Dynamic Variable

  No

  Value Set

  Type

  filename

  The path to the data directory.

• --debug[=debug_options], -# [debug_options]

  Command Line Format

  --debug[=debug_options]

  Config File Format

  debug

  Variable Name

  debug

  Variable Scope

  Both

  Dynamic Variable

  Yes

  Value Set

  Type	string
  Default	'd:t:o,/tmp/mysqld.trace

  If MySQL is configured with --with-debug, you can use this option to get a trace
  file of what mysqld is doing. A typical debug_options string is 'd:t:o,file_name'.
  The default is 'd:t:i:o,mysqld.trace'. See MySQL
  Internals: Porting.

  As of MySQL 5.1.12, using --with-debug to configure MySQL with debugging support
  enables you to use the --debug="d,parser_debug" option when you start the
  server. This causes the Bison parser that is used to process SQL statements to
  dump a parser trace to the server's standard error output. Typically, this
  output is written to the error log.

  This option may be given multiple times. Values that begin with + or - are added to or
  subtracted from the previous value. For example, --debug=T --debug=+P
  sets the value to P:T.

• --default-character-set=charset_name (DEPRECATED)

  Command Line Format

  --default-character-set=name

  Config File Format

  default-character-set

  Deprecated

  5.0

  Value Set

  Type

  string

  Use charset_name as the default
  character set. This option is deprecated in favor of --character-set-server. See Section 9.2, “The Character Set Used for Data and
  Sorting”.

• --default-collation=collation_name

  Command Line Format

  --default-collation=name

  Variable Name

  default-collation

  Variable Scope

  Dynamic Variable

  No

  Deprecated

  4.1.3

  Value Set

  Type

  string

  Use collation_name as the default
  collation. This option is deprecated in favor of --collation-server. See Section 9.2, “The Character Set Used for Data and
  Sorting”.

• --default-storage-engine=type

  Command Line Format	--default-storage-engine=name
  Config File Format	default-storage-engine

  Set the default storage engine (table type) for tables. See Chapter 13, Storage
  Engines.

• --default-table-type=type

  Command Line Format

  --default-table-type=name

  Config File Format

  default-table-type

  Deprecated

  5.0, by default-storage-engine

  Value Set

  Type

  string

  This option is a deprecated synonym for --default-storage-engine.

• --default-time-zone=timezone

  Command Line Format

  --default-time-zone=name

  Config File Format

  default-time-zone

  Value Set

  Type

  string

  Set the default server time zone. This option sets the global time_zone
  system variable. If this option is not given, the default time zone is the same
  as the system time zone (given by the value of the system_time_zone system variable.

• --delay-key-write[={OFF|ON|ALL}]

  Command Line Format

  --delay-key-write[=name]

  Config File Format

  delay-key-write

  Option Sets Variable

  Yes, delay_key_write

  Variable Name

  delay-key-write

  Variable Scope

  Global

  Dynamic Variable

  Yes

  Value Set

  Type	enumeration
  Default	ON
  Valid Values	ON, OFF, ALL

  Specify how to use delayed key writes. Delayed key writing causes key buffers
  not to be flushed between writes for MyISAM tables.
  OFF disables delayed key writes. ON enables delayed key writes for those tables that were
  created with the DELAY_KEY_WRITE option. ALL delays key writes for all MyISAM tables. See Section 7.5.3, “Tuning Server
  Parameters”, and Section 13.5.1, “MyISAM Startup Options”.

  Note

  If you set this variable to ALL, you should not
  use MyISAM tables from within another program (such
  as another MySQL server or myisamchk) when the tables are in use. Doing
  so leads to index corruption.

• --des-key-file=file_name

  Command Line Format	--des-key-file=name
  Config File Format	des-key-file

  Read the default DES keys from this file. These keys are used by the DES_ENCRYPT() and DES_DECRYPT() functions.

• --enable-named-pipe

  Command Line Format	--named_pipe
  Config File Format	enable-named-pipe
  Platform Specific	windows

  Enable support for named pipes. This option applies only on Windows NT, 2000,
  XP, and 2003 systems. For MySQL 5.1.20 and earlier, this option is available
  only when using the mysqld-nt and mysqld-debug servers that support named-pipe connections.
  For MySQL 5.1.21 and later, mysqld-nt is not available, but support is
  included in the standard mysqld and mysqld-debug servers.

• --enable-pstack

  Command Line Format

  --enable-pstack

  Config File Format

  enable-pstack

  Value Set

  Type	boolean
  Default	FALSE

  Print a symbolic stack trace on failure.

• --engine-condition-pushdown={ON|OFF}

  Command Line Format

  --engine-condition-pushdown

  Config File Format

  engine-condition-pushdown

  Option Sets Variable

  Yes, engine_condition_pushdown

  Variable Name

  engine_condition_pushdown

  Variable Scope

  Both

  Dynamic Variable

  Yes

  Value Set (>= 5.1.0)

  Type	boolean
  Default	ON

  Sets the engine_condition_pushdown system variable. For more
  information, see Section 7.2.7, “Condition
  Pushdown Optimization”.

• --event-scheduler[=value]

  Version Introduced

  5.1.6

  Command Line Format

  --event-scheduler[=value]

  Config File Format

  event-scheduler

  Option Sets Variable

  Yes, event_scheduler

  Variable Name

  event_scheduler

  Variable Scope

  Global

  Dynamic Variable

  Yes

  Value Set

  Type	enumeration
  Default	OFF
  Valid Values	ON, OFF, DISABLED

  Enable or disable, and start or stop, the event scheduler. This option was
  added in MySQL 5.1.6. Note that its permitted values and behaviour changed in
  MySQL 5.1.11, and again in MySQL 5.1.12.

  For detailed information, see The event-scheduler Option.

• --exit-info[=flags], -T
[flags]

  Command Line Format

  --exit-info[=flags]

  Config File Format

  exit-info

  Value Set

  Type

  numeric

  This is a bit mask of different flags that you can use for debugging the mysqld server. Do not use this option unless
  you know exactly what it does!

• --external-locking

  Command Line Format

  --external-locking

  Config File Format

  external-locking

  Option Sets Variable

  Yes, skip_external_locking

  Disabled by

  skip-external-locking

  Value Set

  Type	boolean
  Default	FALSE

  Enable external locking (system locking), which is disabled by default as of
  MySQL 4.0. Note that if you use this option on a system on which lockd does not fully work (such as Linux), it is easy for
  mysqld to deadlock. This option previously was
  named --enable-locking.

  For more information about external locking, including conditions under which
  it can and cannot be used, see Section 7.3.4, “External Locking”.

• --flush

  Command Line Format

  --flush

  Config File Format

  flush

  Variable Name

  flush

  Variable Scope

  Global

  Dynamic Variable

  Yes

  Value Set

  Type	boolean
  Default	OFF

  Flush (synchronize) all changes to disk after each SQL statement. Normally,
  MySQL does a write of all changes to disk only after each SQL statement and lets
  the operating system handle the synchronizing to disk. See Section B.1.4.2, “What to Do If MySQL Keeps
  Crashing”.

• --gdb

  Command Line Format

  --gdb

  Config File Format

  gdb

  Value Set

  Type	boolean
  Default	FALSE

  Install an interrupt handler for SIGINT (needed to
  stop mysqld with ^C to
  set breakpoints) and disable stack tracing and core file handling. See MySQL
  Internals: Porting.

• --general-log[={0|1}]

  Version Introduced

  5.1.12

  Command Line Format

  --general-log

  Config File Format

  general-log

  Option Sets Variable

  Yes, general_log

  Variable Name

  general_log

  Variable Scope

  Global

  Dynamic Variable

  Yes

  Value Set

  Type	boolean
  Default	OFF

  Specify the initial general query log state. With no argument or an argument
  of 1, the --general-log option enables the log. If omitted or
  given with an argument of 0, the option disables the log. This option was added
  in MySQL 5.1.12.

• --init-file=file_name

  Command Line Format

  --init-file=name

  Config File Format

  init-file

  Option Sets Variable

  Yes, init_file

  Variable Name

  init_file

  Variable Scope

  Global

  Dynamic Variable

  No

  Value Set

  Type

  filename

  Read SQL statements from this file at startup. Each statement must be on a
  single line and should not include comments.

  This option is unavailable if MySQL was configured with the --disable-grant-options option. See Section 2.10.2, “Typical configure Options”.

• --innodb-xxx

  The InnoDB options are listed in