6.5.4 mysqldump — A Database Backup Program (original) (raw)

6.5.4 mysqldump — A Database Backup Program

The mysqldump client utility performslogical backups, producing a set of SQL statements that can be executed to reproduce the original database object definitions and table data. It dumps one or more MySQL databases for backup or transfer to another SQL server. The mysqldump command can also generate output in CSV, other delimited text, or XML format.

Tip

Consider using the MySQL Shell dump utilities, which provide parallel dumping with multiple threads, file compression, and progress information display, as well as cloud features such as Oracle Cloud Infrastructure Object Storage streaming, and MySQL HeatWave Service compatibility checks and modifications. Dumps can be easily imported into a MySQL Server instance or a MySQL HeatWave Service DB System using the MySQL Shell load dump utilities. Installation instructions for MySQL Shell can be found here.

• Performance and Scalability Considerations
• Invocation Syntax
• Option Syntax - Alphabetical Summary
• Connection Options
• Option-File Options
• DDL Options
• Debug Options
• Help Options
• Internationalization Options
• Replication Options
• Format Options
• Filtering Options
• Performance Options
• Transactional Options
• Option Groups
• Examples
• Restrictions

mysqldump requires at least theSELECT privilege for dumped tables, SHOW VIEW for dumped views, TRIGGER for dumped triggers, LOCK TABLES if the--single-transaction option is not used, PROCESS if the--no-tablespaces option is not used, and theRELOAD orFLUSH_TABLES privilege with--single-transaction if both gtid_mode=ON and gtid_purged=ON|AUTO. Certain options might require other privileges as noted in the option descriptions.

To reload a dump file, you must have the privileges required to execute the statements that it contains, such as the appropriateCREATE privileges for objects created by those statements.

mysqldump output can includeALTER DATABASE statements that change the database collation. These may be used when dumping stored programs to preserve their character encodings. To reload a dump file containing such statements, theALTER privilege for the affected database is required.

Note

A dump made using PowerShell on Windows with output redirection creates a file that has UTF-16 encoding:

mysqldump [options] > dump.sql

However, UTF-16 is not permitted as a connection character set (seeImpermissible Client Character Sets), so the dump file cannot be loaded correctly. To work around this issue, use the --result-file option, which creates the output in ASCII format:

mysqldump [options] --result-file=dump.sql

It is not recommended to load a dump file when GTIDs are enabled on the server (gtid_mode=ON), if your dump file includes system tables.mysqldump issues DML instructions for the system tables which use the non-transactional MyISAM storage engine, and this combination is not permitted when GTIDs are enabled.

Performance and Scalability Considerations

mysqldump advantages include the convenience and flexibility of viewing or even editing the output before restoring. You can clone databases for development and DBA work, or produce slight variations of an existing database for testing. It is not intended as a fast or scalable solution for backing up substantial amounts of data. With large data sizes, even if the backup step takes a reasonable time, restoring the data can be very slow because replaying the SQL statements involves disk I/O for insertion, index creation, and so on.

For large-scale backup and restore, aphysical backup is more appropriate, to copy the data files in their original format so that they can be restored quickly.

If your tables are primarily InnoDB tables, or if you have a mix of InnoDB andMyISAM tables, consider usingmysqlbackup, which is available as part of MySQL Enterprise. This tool provides high performance forInnoDB backups with minimal disruption; it can also back up tables from MyISAM and other storage engines; it also provides a number of convenient options to accommodate different backup scenarios. SeeSection 32.1, “MySQL Enterprise Backup Overview”.

mysqldump can retrieve and dump table contents row by row, or it can retrieve the entire content from a table and buffer it in memory before dumping it. Buffering in memory can be a problem if you are dumping large tables. To dump tables row by row, use the--quick option (or--opt, which enables--quick). The--opt option (and hence--quick) is enabled by default, so to enable memory buffering, use--skip-quick.

If you are using a recent version ofmysqldump to generate a dump to be reloaded into a very old MySQL server, use the--skip-opt option instead of the --opt or--extended-insert option.

For additional information about mysqldump, see Section 9.4, “Using mysqldump for Backups”.

Invocation Syntax

There are in general three ways to usemysqldump—in order to dump a set of one or more tables, a set of one or more complete databases, or an entire MySQL server—as shown here:

mysqldump [options] db_name [tbl_name ...]
mysqldump [options] --databases db_name ...
mysqldump [options] --all-databases

To dump entire databases, do not name any tables following_dbname_, or use the--databases or--all-databases option.

To see a list of the options your version ofmysqldump supports, issue the commandmysqldump --help.

Option Syntax - Alphabetical Summary

mysqldump supports the following options, which can be specified on the command line or in the[mysqldump] and [client] groups of an option file. For information about option files used by MySQL programs, see Section 6.2.2.2, “Using Option Files”.

Connection Options

The mysqldump command logs into a MySQL server to extract information. The following options specify how to connect to the MySQL server, either on the same machine or a remote system.

• --bind-address=ip_address

  Command-Line Format	--bind-address=ip_address
  On a computer having multiple network interfaces, use this option to select which interface to use for connecting to the MySQL server.

• --compress,-C

  Command-Line Format	--compress[={OFF|ON}]
  Deprecated	Yes
  Type	Boolean
  Default Value	OFF
  Compress all information sent between the client and the server if possible. SeeSection 6.2.8, “Connection Compression Control”.
  This option is deprecated. Expect it to be removed in a future version of MySQL. SeeConfiguring Legacy Connection Compression.

• --compression-algorithms=value

  Command-Line Format	--compression-algorithms=value
  Type	Set
  Default Value	uncompressed
  Valid Values	zlibzstduncompressed
  The permitted compression algorithms for connections to the server. The available algorithms are the same as for theprotocol_compression_algorithms system variable. The default value isuncompressed.
  For more information, seeSection 6.2.8, “Connection Compression Control”.

• --default-auth=plugin

  Command-Line Format	--default-auth=plugin
  Type	String
  A hint about which client-side authentication plugin to use. See Section 8.2.17, “Pluggable Authentication”.

• --enable-cleartext-plugin

  Command-Line Format	--enable-cleartext-plugin
  Type	Boolean
  Default Value	FALSE
  Enable the mysql_clear_password cleartext authentication plugin. (SeeSection 8.4.1.4, “Client-Side Cleartext Pluggable Authentication”.)

• --get-server-public-key

  Command-Line Format	--get-server-public-key
  Type	Boolean
  Request from the server the public key required for RSA key pair-based password exchange. This option applies to clients that authenticate with thecaching_sha2_password authentication plugin. For that plugin, the server does not send the public key unless requested. This option is ignored for accounts that do not authenticate with that plugin. It is also ignored if RSA-based password exchange is not used, as is the case when the client connects to the server using a secure connection.
  If--server-public-key-path=file_name is given and specifies a valid public key file, it takes precedence over--get-server-public-key.
  For information about thecaching_sha2_password plugin, seeSection 8.4.1.2, “Caching SHA-2 Pluggable Authentication”.

• --host=host_name,-h _`hostname`_

  Command-Line Format	--host
  Dump data from the MySQL server on the given host. The default host is localhost.

• --login-path=name

  Command-Line Format	--login-path=name
  Type	String
  Read options from the named login path in the.mylogin.cnf login path file. A“login path” is an option group containing options that specify which MySQL server to connect to and which account to authenticate as. To create or modify a login path file, use themysql_config_editor utility. SeeSection 6.6.7, “mysql_config_editor — MySQL Configuration Utility”.
  For additional information about this and other option-file options, see Section 6.2.2.3, “Command-Line Options that Affect Option-File Handling”.

• --no-login-paths

  Command-Line Format	--no-login-paths
  Skips reading options from the login path file.
  See --login-path for related information.
  For additional information about this and other option-file options, see Section 6.2.2.3, “Command-Line Options that Affect Option-File Handling”.

• --password[=password],-p[_`password`_]

  Command-Line Format	--password[=password]
  Type	String
  The password of the MySQL account used for connecting to the server. The password value is optional. If not given,mysqldump prompts for one. If given, there must be no space between--password= or-p and the password following it. If no password option is specified, the default is to send no password.
  Specifying a password on the command line should be considered insecure. To avoid giving the password on the command line, use an option file. SeeSection 8.1.2.1, “End-User Guidelines for Password Security”.
  To explicitly specify that there is no password and thatmysqldump should not prompt for one, use the--skip-password option.

• --password1[=pass_val]
  The password for multifactor authentication factor 1 of the MySQL account used for connecting to the server. The password value is optional. If not given,mysqldump prompts for one. If given, there must be no space between--password1= and the password following it. If no password option is specified, the default is to send no password.
  Specifying a password on the command line should be considered insecure. To avoid giving the password on the command line, use an option file. SeeSection 8.1.2.1, “End-User Guidelines for Password Security”.
  To explicitly specify that there is no password and thatmysqldump should not prompt for one, use the--skip-password1 option.
  --password1 and--password are synonymous, as are--skip-password1 and--skip-password.
• --password2[=pass_val]
  The password for multifactor authentication factor 2 of the MySQL account used for connecting to the server. The semantics of this option are similar to the semantics for--password1; see the description of that option for details.
• --password3[=pass_val]
  The password for multifactor authentication factor 3 of the MySQL account used for connecting to the server. The semantics of this option are similar to the semantics for--password1; see the description of that option for details.
• --pipe,-W

  Command-Line Format	--pipe
  Type	String
  On Windows, connect to the server using a named pipe. This option applies only if the server was started with thenamed_pipe system variable enabled to support named-pipe connections. In addition, the user making the connection must be a member of the Windows group specified by thenamed_pipe_full_access_group system variable.

• --plugin-authentication-kerberos-client-mode=value

  Command-Line Format	--plugin-authentication-kerberos-client-mode
  Type	String
  Default Value	SSPI
  Valid Values	GSSAPI
  On Windows, theauthentication_kerberos_client authentication plugin supports this plugin option. It provides two possible values that the client user can set at runtime: SSPI andGSSAPI.
  The default value for the client-side plugin option uses Security Support Provider Interface (SSPI), which is capable of acquiring credentials from the Windows in-memory cache. Alternatively, the client user can select a mode that supports Generic Security Service Application Program Interface (GSSAPI) through the MIT Kerberos library on Windows. GSSAPI is capable of acquiring cached credentials previously generated by using the kinit command.
  For more information, seeCommands for Windows Clients in GSSAPI Mode.

• --plugin-dir=dir_name

  Command-Line Format	--plugin-dir=dir_name
  Type	Directory name
  The directory in which to look for plugins. Specify this option if the--default-auth option is used to specify an authentication plugin butmysqldump does not find it. SeeSection 8.2.17, “Pluggable Authentication”.

• --port=port_num,-P _`portnum`_

  Command-Line Format	--port=port_num
  Type	Numeric
  Default Value	3306
  For TCP/IP connections, the port number to use.

• --protocol={TCP|SOCKET|PIPE|MEMORY}

  Command-Line Format	--protocol=type
  Type	String
  Default Value	[see text]
  Valid Values	TCPSOCKETPIPEMEMORY
  The transport protocol to use for connecting to the server. It is useful when the other connection parameters normally result in use of a protocol other than the one you want. For details on the permissible values, seeSection 6.2.7, “Connection Transport Protocols”.

• --server-public-key-path=file_name

  Command-Line Format	--server-public-key-path=file_name
  Type	File name
  The path name to a file in PEM format containing a client-side copy of the public key required by the server for RSA key pair-based password exchange. This option applies to clients that authenticate with thesha256_password (deprecated) orcaching_sha2_password authentication plugin. This option is ignored for accounts that do not authenticate with one of those plugins. It is also ignored if RSA-based password exchange is not used, as is the case when the client connects to the server using a secure connection.
  If--server-public-key-path=file_name is given and specifies a valid public key file, it takes precedence over--get-server-public-key.
  For sha256_password (deprecated), this option applies only if MySQL was built using OpenSSL.
  For information about the sha256_password and caching_sha2_password plugins, seeSection 8.4.1.3, “SHA-256 Pluggable Authentication”, andSection 8.4.1.2, “Caching SHA-2 Pluggable Authentication”.

• --socket=path,-S _`path`_

  Command-Line Format	--socket={file_name|pipe_name}
  Type	String
  For connections to localhost, the Unix socket file to use, or, on Windows, the name of the named pipe to use.
  On Windows, this option applies only if the server was started with the named_pipe system variable enabled to support named-pipe connections. In addition, the user making the connection must be a member of the Windows group specified by thenamed_pipe_full_access_group system variable.

• --ssl*
  Options that begin with --ssl specify whether to connect to the server using encryption and indicate where to find SSL keys and certificates. SeeCommand Options for Encrypted Connections.
• --ssl-fips-mode={OFF|ON|STRICT}
  | Command-Line Format | --ssl-fips-mode={OFF|ON|STRICT} |
  | ------------------- | --------------------------------- |
  | Deprecated | Yes |
  | Type | Enumeration |
  | Default Value | OFF |
  | Valid Values | OFFONSTRICT |
  Controls whether to enable FIPS mode on the client side. The--ssl-fips-mode option differs from other--ssl-_`xxx`_ options in that it is not used to establish encrypted connections, but rather to affect which cryptographic operations to permit. See Section 8.8, “FIPS Support”.
  These --ssl-fips-mode values are permitted:
  • OFF: Disable FIPS mode.
  • ON: Enable FIPS mode.
  • STRICT: Enable “strict” FIPS mode.
    Note
    If the OpenSSL FIPS Object Module is not available, the only permitted value for--ssl-fips-mode isOFF. In this case, setting--ssl-fips-mode toON or STRICT causes the client to produce a warning at startup and to operate in non-FIPS mode.
    This option is deprecated. Expect it to be removed in a future version of MySQL.
• --tls-ciphersuites=ciphersuite_list

  Command-Line Format	--tls-ciphersuites=ciphersuite_list
  Type	String
  The permissible ciphersuites for encrypted connections that use TLSv1.3. The value is a list of one or more colon-separated ciphersuite names. The ciphersuites that can be named for this option depend on the SSL library used to compile MySQL. For details, seeSection 8.3.2, “Encrypted Connection TLS Protocols and Ciphers”.

• --tls-sni-servername=server_name

  Command-Line Format	--tls-sni-servername=server_name
  Type	String
  When specified, the name is passed to thelibmysqlclient C API library using theMYSQL_OPT_TLS_SNI_SERVERNAME option ofmysql_options(). The server name is not case-sensitive. To show which server name the client specified for the current session, if any, check theTls_sni_server_name status variable.
  Server Name Indication (SNI) is an extension to the TLS protocol (OpenSSL must be compiled using TLS extensions for this option to function). The MySQL implementation of SNI represents the client-side only.

• --tls-version=protocol_list

  Command-Line Format	--tls-version=protocol_list
  Type	String
  Default Value	TLSv1,TLSv1.1,TLSv1.2,TLSv1.3 (OpenSSL 1.1.1 or higher)TLSv1,TLSv1.1,TLSv1.2 (otherwise)
  The permissible TLS protocols for encrypted connections. The value is a list of one or more comma-separated protocol names. The protocols that can be named for this option depend on the SSL library used to compile MySQL. For details, seeSection 8.3.2, “Encrypted Connection TLS Protocols and Ciphers”.

• --user=user_name,-u _`username`_

  Command-Line Format	--user=user_name
  Type	String
  The user name of the MySQL account to use for connecting to the server.
  If you are using the Rewriter plugin, you should grant this user theSKIP_QUERY_REWRITE privilege.

• --zstd-compression-level=level

  Command-Line Format	--zstd-compression-level=#
  Type	Integer
  The compression level to use for connections to the server that use the zstd compression algorithm. The permitted levels are from 1 to 22, with larger values indicating increasing levels of compression. The defaultzstd compression level is 3. The compression level setting has no effect on connections that do not use zstd compression.
  For more information, seeSection 6.2.8, “Connection Compression Control”.

Option-File Options

These options are used to control which option files to read.

• --defaults-extra-file=file_name

  Command-Line Format	--defaults-extra-file=file_name
  Type	File name
  Read this option file after the global option file but (on Unix) before the user option file. If the file does not exist or is otherwise inaccessible, an error occurs. If_filename_ is not an absolute path name, it is interpreted relative to the current directory.
  For additional information about this and other option-file options, see Section 6.2.2.3, “Command-Line Options that Affect Option-File Handling”.

• --defaults-file=file_name

  Command-Line Format	--defaults-file=file_name
  Type	File name
  Use only the given option file. If the file does not exist or is otherwise inaccessible, an error occurs. If_filename_ is not an absolute path name, it is interpreted relative to the current directory.
  Exception: Even with--defaults-file, client programs read .mylogin.cnf.
  For additional information about this and other option-file options, see Section 6.2.2.3, “Command-Line Options that Affect Option-File Handling”.

• --defaults-group-suffix=str

  Command-Line Format	--defaults-group-suffix=str
  Type	String
  Read not only the usual option groups, but also groups with the usual names and a suffix of_str_. For example,mysqldump normally reads the[client] and[mysqldump] groups. If this option is given as--defaults-group-suffix=_other,mysqldump also reads the[client_other] and[mysqldump_other] groups.
  For additional information about this and other option-file options, see Section 6.2.2.3, “Command-Line Options that Affect Option-File Handling”.

• --no-defaults

  Command-Line Format	--no-defaults
  Do not read any option files. If program startup fails due to reading unknown options from an option file,--no-defaults can be used to prevent them from being read.
  The exception is that the .mylogin.cnf file is read in all cases, if it exists. This permits passwords to be specified in a safer way than on the command line even when--no-defaults is used. To create .mylogin.cnf, use themysql_config_editor utility. SeeSection 6.6.7, “mysql_config_editor — MySQL Configuration Utility”.
  For additional information about this and other option-file options, see Section 6.2.2.3, “Command-Line Options that Affect Option-File Handling”.

• --print-defaults

  Command-Line Format	--print-defaults
  Print the program name and all options that it gets from option files.
  For additional information about this and other option-file options, see Section 6.2.2.3, “Command-Line Options that Affect Option-File Handling”.

DDL Options

Usage scenarios for mysqldump include setting up an entire new MySQL instance (including database tables), and replacing data inside an existing instance with existing databases and tables. The following options let you specify which things to tear down and set up when restoring a dump, by encoding various DDL statements within the dump file.

• --add-drop-database

  Command-Line Format	--add-drop-database
  Write a DROP DATABASE statement before each CREATE DATABASE statement. This option is typically used in conjunction with the--all-databases or--databases option because no CREATE DATABASE statements are written unless one of those options is specified.
  Note
  In MySQL 8.4, the mysql schema is considered a system schema that cannot be dropped by end users. If--add-drop-database is used with--all-databases or with--databases where the list of schemas to be dumped includesmysql, the dump file contains aDROP DATABASE `mysql` statement that causes an error when the dump file is reloaded.
  Instead, to use--add-drop-database, use--databases with a list of schemas to be dumped, where the list does not includemysql.

• --add-drop-table

  Command-Line Format	--add-drop-table
  Write a DROP TABLE statement before each CREATE TABLE statement.

• --add-drop-trigger

  Command-Line Format	--add-drop-trigger
  Write a DROP TRIGGER statement before each CREATE TRIGGER statement.

• --all-tablespaces,-Y

  Command-Line Format	--all-tablespaces
  Adds to a table dump all SQL statements needed to create any tablespaces used by an NDB table. This information is not otherwise included in the output from mysqldump. This option is currently relevant only to NDB Cluster tables.

• --no-create-db,-n

  Command-Line Format	--no-create-db
  Suppress the CREATE DATABASE statements that are otherwise included in the output if the--databases or--all-databases option is given.

• --no-create-info,-t

  Command-Line Format	--no-create-info
  Do not write CREATE TABLE statements that create each dumped table.
  Note
  This option does not exclude statements creating log file groups or tablespaces frommysqldump output; however, you can use the --no-tablespaces option for this purpose.

• --no-tablespaces,-y

  Command-Line Format	--no-tablespaces
  This option suppresses all CREATE LOGFILE GROUP and CREATE TABLESPACE statements in the output ofmysqldump.

• --replace

  Command-Line Format	--replace
  Write REPLACE statements rather than INSERT statements.

Debug Options

The following options print debugging information, encode debugging information in the dump file, or let the dump operation proceed regardless of potential problems.

• --allow-keywords

  Command-Line Format	--allow-keywords
  Permit creation of column names that are keywords. This works by prefixing each column name with the table name.

• --comments,-i

  Command-Line Format	--comments
  Write additional information in the dump file such as program version, server version, and host. This option is enabled by default. To suppress this additional information, use --skip-comments.

• --debug[=debug_options],-# [_`debugoptions`_]

  Command-Line Format	--debug[=debug_options]
  Type	String
  Default Value	d:t:o,/tmp/mysqldump.trace
  Write a debugging log. A typical_debugoptions_ string isd:t:o,_`filename`_. The default value isd:t:o,/tmp/mysqldump.trace.
  This option is available only if MySQL was built usingWITH_DEBUG. MySQL release binaries provided by Oracle are not built using this option.

• --debug-check

  Command-Line Format	--debug-check
  Type	Boolean
  Default Value	FALSE
  Print some debugging information when the program exits.
  This option is available only if MySQL was built usingWITH_DEBUG. MySQL release binaries provided by Oracle are not built using this option.

• --debug-info

  Command-Line Format	--debug-info
  Type	Boolean
  Default Value	FALSE
  Print debugging information and memory and CPU usage statistics when the program exits.
  This option is available only if MySQL was built usingWITH_DEBUG. MySQL release binaries provided by Oracle are not built using this option.

• --dump-date

  Command-Line Format	--dump-date
  Type	Boolean
  Default Value	TRUE
  If the --comments option is given, mysqldump produces a comment at the end of the dump of the following form:

-- Dump completed on DATE  

However, the date causes dump files taken at different times to appear to be different, even if the data are otherwise identical. --dump-date and--skip-dump-date control whether the date is added to the comment. The default is --dump-date (include the date in the comment).--skip-dump-date suppresses date printing.

• --force,-f

  Command-Line Format	--force
  Ignore all errors; continue even if an SQL error occurs during a table dump.
  One use for this option is to causemysqldump to continue executing even when it encounters a view that has become invalid because the definition refers to a table that has been dropped. Without--force, mysqldump exits with an error message. With --force,mysqldump prints the error message, but it also writes an SQL comment containing the view definition to the dump output and continues executing.
  If the --ignore-error option is also given to ignore specific errors,--force takes precedence.

• --log-error=file_name

  Command-Line Format	--log-error=file_name
  Type	File name
  Log warnings and errors by appending them to the named file. The default is to do no logging.

• --skip-comments

  Command-Line Format	--skip-comments
  See the description for the--comments option.

• --verbose,-v

  Command-Line Format	--verbose
  Verbose mode. Print more information about what the program does.

Help Options

The following options display information about themysqldump command itself.

• --help,-?

  Command-Line Format	--help
  Display a help message and exit.

• --version,-V

  Command-Line Format	--version
  Display version information and exit.

Internationalization Options

The following options change how themysqldump command represents character data with national language settings.

• --character-sets-dir=dir_name

  Command-Line Format	--character-sets-dir=dir_name
  Type	Directory name
  The directory where character sets are installed. SeeSection 12.15, “Character Set Configuration”.

• --default-character-set=charset_name

  Command-Line Format	--default-character-set=charset_name
  Type	String
  Default Value	utf8
  Use charsetname as the default character set. See Section 12.15, “Character Set Configuration”. If no character set is specified,mysqldump usesutf8mb4.

• --no-set-names,-N

  Command-Line Format	--no-set-names
  Deprecated	Yes
  Turns off the--set-charset setting, the same as specifying --skip-set-charset.

• --set-charset

  Command-Line Format	--set-charset
  Disabled by	skip-set-charset
  Write SET NAMES_default_character_set_ to the output. This option is enabled by default. To suppress the SET NAMES statement, use--skip-set-charset.

Replication Options

The mysqldump command is frequently used to create an empty instance, or an instance including data, on a replica server in a replication configuration. The following options apply to dumping and restoring data on replication source servers and replicas.

• --apply-replica-statements

  Command-Line Format	--apply-replica-statements
  Type	Boolean
  Default Value	FALSE
  For a replica dump produced with the--dump-replica option, this option adds aSTOP REPLICA statement before the statement with the binary log coordinates, and aSTART REPLICA statement at the end of the output.

• --apply-slave-statements

  Command-Line Format	--apply-slave-statements
  Deprecated	Yes
  Type	Boolean
  Default Value	FALSE
  This is a deprecated alias for--apply-replica-statements.

• --delete-source-logs

  Command-Line Format	--delete-source-logs
  On a replication source server, delete the binary logs by sending a PURGE BINARY LOGS statement to the server after performing the dump operation. The options require theRELOAD privilege as well as privileges sufficient to execute that statement. This option automatically enables--source-data.

• --delete-master-logs

  Command-Line Format	--delete-master-logs
  Deprecated	Yes
  This is a deprecated alias for--delete-source-logs.

• --dump-replica[=value]

  Command-Line Format	--dump-replica[=value]
  Type	Numeric
  Default Value	1
  Valid Values	12
  This option is similar to--source-data, except that it is used to dump a replica server to produce a dump file that can be used to set up another server as a replica that has the same source as the dumped server. The option causes the dump output to include a CHANGE REPLICATION SOURCE TO statement that indicates the binary log coordinates (file name and position) of the dumped replica's source. TheCHANGE REPLICATION SOURCE TO statement reads the values ofRelay_Master_Log_File andExec_Master_Log_Pos from theSHOW REPLICA STATUS output and uses them forSOURCE_LOG_FILE andSOURCE_LOG_POS respectively. These are the replication source server coordinates from which the replica starts replicating.
  --dump-replica causes the coordinates from the source to be used rather than those of the dumped server, as is done by the--source-data option. In addition, specifying this option overrides the--source-data option.
  Warning
  --dump-replica should not be used if the server where the dump is going to be applied usesgtid_mode=ON andSOURCE_AUTO_POSITION=1.
  The option value is handled the same way as for--source-data. Setting no value or 1 causes a CHANGE REPLICATION SOURCE TO statement to be written to the dump. Setting 2 causes the statement to be written but encased in SQL comments. It has the same effect as--source-data in terms of enabling or disabling other options and in how locking is handled.
  --dump-replica causesmysqldump to stop the replication SQL thread before the dump and restart it again after.
  --dump-replica sends aSHOW REPLICA STATUS statement to the server to obtain information, so they require privileges sufficient to execute that statement.
  --apply-replica-statements and--include-source-host-port options can be used in conjunction with--dump-replica.

• --dump-slave[=value]

  Command-Line Format	--dump-slave[=value]
  Deprecated	Yes
  Type	Numeric
  Default Value	1
  Valid Values	12
  This is a deprecated alias for--dump-replica.

• --include-source-host-port

  Command-Line Format	--include-source-host-port
  Type	Boolean
  Default Value	FALSE
  Adds the SOURCE_HOST andSOURCE_PORT options for the host name and TCP/IP port number of the replica's source, to theCHANGE REPLICATION SOURCE TO statement in a replica dump produced with the--dump-replica option.

• --include-master-host-port

  Command-Line Format	--include-master-host-port
  Deprecated	Yes
  Type	Boolean
  Default Value	FALSE
  This is a deprecated alias for--include-source-host-port.

• --master-data[=value]

  Command-Line Format	--master-data[=value]
  Deprecated	Yes
  Type	Numeric
  Default Value	1
  Valid Values	12
  This is a deprecated alias for--source-data.

• --output-as-version=value

  Command-Line Format	--output-as-version=value
  Type	Enumeration
  Default Value	SERVER
  Valid Values	BEFORE_8_0_23BEFORE_8_2_0
  Determines the level of terminology used for statements relating to replicas and events, making it possible to create dumps compatible with older versions of MySQL that do not accept the newer terminology. This option can take any one of the following values, with effects described as listed here:

  • SERVER: Reads the server version and uses the latest versions of statements compatible with that version. This is the default value.
  • BEFORE_8_0_23: Replication SQL statements using deprecated terms such as“slave” and “master” are written to the output in place of those using“replica” and “source”, as in MySQL versions prior to 8.0.23.
    This option also duplicates the effects ofBEFORE_8_2_0 on the output ofSHOW CREATE EVENT.
  • BEFORE_8_2_0: This option causesSHOW CREATE EVENT to reflect how the event would have been created in a MySQL server prior to version 8.2.0, displayingDISABLE ON SLAVE rather thanDISABLE ON REPLICA.
    This option affects the output from--events,--dump-replica,--source-data,--apply-replica-statements, and--include-source-host-port.
• --source-data[=value]

  Command-Line Format	--source-data[=value]
  Type	Numeric
  Default Value	1
  Valid Values	12
  Used to dump a replication source server to produce a dump file that can be used to set up another server as a replica of the source. The options cause the dump output to include a CHANGE REPLICATION SOURCE TO statement that indicates the binary log coordinates (file name and position) of the dumped server. These are the replication source server coordinates from which the replica should start replicating after you load the dump file into the replica.
  If the option value is 2, the CHANGE REPLICATION SOURCE TO statement is written as an SQL comment, and thus is informative only; it has no effect when the dump file is reloaded. If the option value is 1, the statement is not written as a comment and takes effect when the dump file is reloaded. If no option value is specified, the default value is 1.
  --source-data sends aSHOW BINARY LOG STATUS statement to the server to obtain information, so they require privileges sufficient to execute that statement. This option also requires theRELOAD privilege and the binary log must be enabled.
  --source-data automatically turns off--lock-tables. They also turn on --lock-all-tables, unless--single-transaction also is specified, in which case, a global read lock is acquired only for a short time at the beginning of the dump (see the description for--single-transaction). In all cases, any action on logs happens at the exact moment of the dump.
  It is also possible to set up a replica by dumping an existing replica of the source, using the--dump-replica option, which overrides --source-data causing it to be ignored.

• --set-gtid-purged=value

  Command-Line Format	--set-gtid-purged=value
  Type	Enumeration
  Default Value	AUTO
  Valid Values	OFFONAUTO
  This option is for servers that use GTID-based replication (gtid_mode=ON). It controls the inclusion of a SET @@GLOBAL.gtid_purged statement in the dump output, which updates the value ofgtid_purged on a server where the dump file is reloaded, to add the GTID set from the source server'sgtid_executed system variable. gtid_purged holds the GTIDs of all transactions that have been applied on the server, but do not exist on any binary log file on the server. mysqldump therefore adds the GTIDs for the transactions that were executed on the source server, so that the target server records these transactions as applied, although it does not have them in its binary logs. --set-gtid-purged also controls the inclusion of a SET @@SESSION.sql_log_bin=0 statement, which disables binary logging while the dump file is being reloaded. This statement prevents new GTIDs from being generated and assigned to the transactions in the dump file as they are executed, so that the original GTIDs for the transactions are used.
  If you do not set the --set-gtid-purged option, the default is that a SET @@GLOBAL.gtid_purged statement is included in the dump output if GTIDs are enabled on the server you are backing up, and the set of GTIDs in the global value of thegtid_executed system variable is not empty. A SET @@SESSION.sql_log_bin=0 statement is also included if GTIDs are enabled on the server.
  You can either replace the value ofgtid_purged with a specified GTID set, or add a plus sign (+) to the statement to append a specified GTID set to the GTID set that is already held by gtid_purged. TheSET @@GLOBAL.gtid_purged statement recorded by mysqldump includes a plus sign (+) in a version-specific comment, such that MySQL adds the GTID set from the dump file to the existing gtid_purged value.
  It is important to note that the value that is included bymysqldump for the SET @@GLOBAL.gtid_purged statement includes the GTIDs of all transactions in thegtid_executed set on the server, even those that changed suppressed parts of the database, or other databases on the server that were not included in a partial dump. This can mean that after thegtid_purged value has been updated on the server where the dump file is replayed, GTIDs are present that do not relate to any data on the target server. If you do not replay any further dump files on the target server, the extraneous GTIDs do not cause any problems with the future operation of the server, but they make it harder to compare or reconcile GTID sets on different servers in the replication topology. If you do replay a further dump file on the target server that contains the same GTIDs (for example, another partial dump from the same origin server), any SET @@GLOBAL.gtid_purged statement in the second dump file fails. In this case, either remove the statement manually before replaying the dump file, or output the dump file without the statement.
  If the SET @@GLOBAL.gtid_purged statement would not have the desired result on your target server, you can exclude the statement from the output, or include it but comment it out so that it is not actioned automatically. You can also include the statement but manually edit it in the dump file to achieve the desired result.
  The possible values for the--set-gtid-purged option are as follows:
  AUTO
  The default value. If GTIDs are enabled on the server you are backing up andgtid_executed is not empty, SET @@GLOBAL.gtid_purged is added to the output, containing the GTID set fromgtid_executed. If GTIDs are enabled, SET @@SESSION.sql_log_bin=0 is added to the output. If GTIDs are not enabled on the server, the statements are not added to the output.
  OFF
  SET @@GLOBAL.gtid_purged is not added to the output, and SET @@SESSION.sql_log_bin=0 is not added to the output. For a server where GTIDs are not in use, use this option or AUTO. Only use this option for a server where GTIDs are in use if you are sure that the required GTID set is already present ingtid_purged on the target server and should not be changed, or if you plan to identify and add any missing GTIDs manually.
  ON
  If GTIDs are enabled on the server you are backing up,SET @@GLOBAL.gtid_purged is added to the output (unlessgtid_executed is empty), and SET @@SESSION.sql_log_bin=0 is added to the output. An error occurs if you set this option but GTIDs are not enabled on the server. For a server where GTIDs are in use, use this option orAUTO, unless you are sure that the GTIDs ingtid_executed are not needed on the target server.
  COMMENTED
  If GTIDs are enabled on the server you are backing up,SET @@GLOBAL.gtid_purged is added to the output (unlessgtid_executed is empty), but it is commented out. This means that the value ofgtid_executed is available in the output, but no action is taken automatically when the dump file is reloaded.SET @@SESSION.sql_log_bin=0 is added to the output, and it is not commented out. WithCOMMENTED, you can control the use of the gtid_executed set manually or through automation. For example, you might prefer to do this if you are migrating data to another server that already has different active databases.

Format Options

The following options specify how to represent the entire dump file or certain kinds of data in the dump file. They also control whether certain optional information is written to the dump file.

• --compact

  Command-Line Format	--compact
  Produce more compact output. This option enables the--skip-add-drop-table,--skip-add-locks,--skip-comments,--skip-disable-keys, and--skip-set-charset options.

• --compatible=name

  Command-Line Format	--compatible=name[,name,...]
  Type	String
  Default Value	''
  Valid Values	ansimysql323mysql40postgresqloraclemssqldb2maxdbno_key_optionsno_table_optionsno_key_options
  Produce output that is more compatible with other database systems or with older MySQL servers. The only permitted value for this option is ansi, which has the same meaning as the corresponding option for setting the server SQL mode. See Section 7.1.11, “Server SQL Modes”.

• --complete-insert,-c

  Command-Line Format	--complete-insert
  Use complete INSERT statements that include column names.

• --create-options

  Command-Line Format	--create-options
  Include all MySQL-specific table options in theCREATE TABLE statements.

• --fields-terminated-by=...,--fields-enclosed-by=...,--fields-optionally-enclosed-by=...,--fields-escaped-by=...

  Command-Line Format	--fields-terminated-by=string
  Type	String
  Command-Line Format	--fields-enclosed-by=string
  -------------------	----------------------------
  Type	String
  Command-Line Format	--fields-optionally-enclosed-by=string
  -------------------	---------------------------------------
  Type	String
  Command-Line Format	--fields-escaped-by
  -------------------	--------------------
  Type	String
  These options are used with the--tab option and have the same meaning as the corresponding FIELDS clauses for LOAD DATA. SeeSection 15.2.9, “LOAD DATA Statement”.

• --hex-blob

  Command-Line Format	--hex-blob
  Dump binary columns using hexadecimal notation (for example,'abc' becomes0x616263). The affected data types areBINARY,VARBINARY,BLOB types,BIT, all spatial data types, and other non-binary data types when used with thebinary character set.
  The --hex-blob option is ignored when the --tab is used.

• --lines-terminated-by=...

  Command-Line Format	--lines-terminated-by=string
  Type	String
  This option is used with the--tab option and has the same meaning as the corresponding LINES clause for LOAD DATA. SeeSection 15.2.9, “LOAD DATA Statement”.

• --quote-names,-Q

  Command-Line Format	--quote-names
  Disabled by	skip-quote-names
  Quote identifiers (such as database, table, and column names) within ` characters. If theANSI_QUOTES SQL mode is enabled, identifiers are quoted within " characters. This option is enabled by default. It can be disabled with --skip-quote-names, but this option should be given after any option such as--compatible that may enable --quote-names.

• --result-file=file_name,-r _`filename`_

  Command-Line Format	--result-file=file_name
  Type	File name
  Direct output to the named file. The result file is created and its previous contents overwritten, even if an error occurs while generating the dump.
  This option should be used on Windows to prevent newline\n characters from being converted to\r\n carriage return/newline sequences.

• --show-create-skip-secondary-engine=value

  Command-Line Format	--show-create-skip-secondary-engine
  Excludes the SECONDARY ENGINE clause fromCREATE TABLE statements. It does so by enabling theshow_create_table_skip_secondary_engine system variable for the duration of the dump operation. Alternatively, you can enable theshow_create_table_skip_secondary_engine system variable prior to using mysqldump.

• --tab=dir_name,-T _`dirname`_

  Command-Line Format	--tab=dir_name
  Type	Directory name
  Produce tab-separated text-format data files. For each dumped table, mysqldump creates a_`tblname`_.sql file that contains the CREATE TABLE statement that creates the table, and the server writes a_`tblname`_.txt file that contains its data. The option value is the directory in which to write the files.
  Note
  This option should be used only whenmysqldump is run on the same machine as the mysqld server. Because the server creates *.txt files in the directory that you specify, the directory must be writable by the server and the MySQL account that you use must have theFILE privilege. Becausemysqldump creates*.sql in the same directory, it must be writable by your system login account.
  By default, the .txt data files are formatted using tab characters between column values and a newline at the end of each line. The format can be specified explicitly using the--fields-_`xxx`_ and--lines-terminated-by options.
  Column values are converted to the character set specified by the--default-character-set option.

• --tz-utc

  Command-Line Format	--tz-utc
  Disabled by	skip-tz-utc
  This option enables TIMESTAMP columns to be dumped and reloaded between servers in different time zones. mysqldump sets its connection time zone to UTC and adds SET TIME_ZONE='+00:00' to the dump file. Without this option, TIMESTAMP columns are dumped and reloaded in the time zones local to the source and destination servers, which can cause the values to change if the servers are in different time zones.--tz-utc also protects against changes due to daylight saving time. --tz-utc is enabled by default. To disable it, use--skip-tz-utc.

• --xml, -X

  Command-Line Format	--xml
  Write dump output as well-formed XML.
  NULL,'NULL', and Empty Values: For a column named columnname, theNULL value, an empty string, and the string value 'NULL' are distinguished from one another in the output generated by this option as follows.
  Value:	XML Representation:
  -----------------------	----------------------------------------------
  NULL (unknown value)
  '' (empty string)
  'NULL' (string value)	NULL
  The output from the mysql client when run using the --xml option also follows the preceding rules. (SeeSection 6.5.1.1, “mysql Client Options”.)
  XML output from mysqldump includes the XML namespace, as shown here:

$> mysqldump --xml -u root world City  
<?xml version="1.0"?>  
<mysqldump xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">  
<database name="world">  
<table_structure name="City">  
<field Field="ID" Type="int(11)" Null="NO" Key="PRI" Extra="auto_increment" />  
<field Field="Name" Type="char(35)" Null="NO" Key="" Default="" Extra="" />  
<field Field="CountryCode" Type="char(3)" Null="NO" Key="" Default="" Extra="" />  
<field Field="District" Type="char(20)" Null="NO" Key="" Default="" Extra="" />  
<field Field="Population" Type="int(11)" Null="NO" Key="" Default="0" Extra="" />  
<key Table="City" Non_unique="0" Key_name="PRIMARY" Seq_in_index="1" Column_name="ID"  
Collation="A" Cardinality="4079" Null="" Index_type="BTREE" Comment="" />  
<options Name="City" Engine="MyISAM" Version="10" Row_format="Fixed" Rows="4079"  
Avg_row_length="67" Data_length="273293" Max_data_length="18858823439613951"  
Index_length="43008" Data_free="0" Auto_increment="4080"  
Create_time="2007-03-31 01:47:01" Update_time="2007-03-31 01:47:02"  
Collation="latin1_swedish_ci" Create_options="" Comment="" />  
</table_structure>  
<table_data name="City">  
<row>  
<field name="ID">1</field>  
<field name="Name">Kabul</field>  
<field name="CountryCode">AFG</field>  
<field name="District">Kabol</field>  
<field name="Population">1780000</field>  
</row>  
...  
<row>  
<field name="ID">4079</field>  
<field name="Name">Rafah</field>  
<field name="CountryCode">PSE</field>  
<field name="District">Rafah</field>  
<field name="Population">92020</field>  
</row>  
</table_data>  
</database>  
</mysqldump>  

Filtering Options

The following options control which kinds of schema objects are written to the dump file: by category, such as triggers or events; by name, for example, choosing which databases and tables to dump; or even filtering rows from the table data using a WHERE clause.

• --all-databases,-A

  Command-Line Format	--all-databases
  Dump all tables in all databases. This is the same as using the --databases option and naming all the databases on the command line.
  Prior to MySQL 8.4, the--routines and--events options formysqldump were not required to include stored routines and events when using the--all-databases option: The dump included the mysql system database, and therefore also themysql.proc andmysql.event tables containing stored routine and event definitions. As of MySQL 8.4, the mysql.event andmysql.proc tables are not used. Definitions for the corresponding objects are stored in data dictionary tables, but those tables are not dumped. To include stored routines and events in a dump made using--all-databases, use the--routines and--events options explicitly.

• --databases,-B

  Command-Line Format	--databases
  Dump several databases. Normally,mysqldump treats the first name argument on the command line as a database name and following names as table names. With this option, it treats all name arguments as database names. CREATE DATABASE and USE statements are included in the output before each new database.
  This option may be used to dump theperformance_schema database, which normally is not dumped even with the--all-databases option. (Also use the--skip-lock-tables option.)

• --events,-E

  Command-Line Format	--events
  Include Event Scheduler events for the dumped databases in the output. This option requires theEVENT privileges for those databases.
  The output generated by using --events contains CREATE EVENT statements to create the events.

• --ignore-error=error[,error]...

  Command-Line Format	--ignore-error=error[,error]...
  Type	String
  Ignore the specified errors. The option value is a list of comma-separated error numbers specifying the errors to ignore during mysqldump execution. If the--force option is also given to ignore all errors,--force takes precedence.

• --ignore-table=db_name.tbl_name

  Command-Line Format	--ignore-table=db_name.tbl_name
  Type	String
  Do not dump the given table, which must be specified using both the database and table names. To ignore multiple tables, use this option multiple times. This option also can be used to ignore views.

• --ignore-views=boolean

  Command-Line Format	--ignore-views
  Type	Boolean
  Default Value	FALSE
  Skips table views in the dump file.

• --init-command=str

  Command-Line Format	--init-command=str
  Type	String
  Single SQL statement to execute after connecting to the MySQL server. The definition resets existing statements defined by it orinit-command-add.

• --init-command-add=str

  Command-Line Format	--init-command-add=str
  Type	String
  Add an additional SQL statement to execute after connecting or reconnecting to the MySQL server. It's usable without--init-command but has no effect if used before it becauseinit-command resets the list of commands to call.

• --no-data,-d

  Command-Line Format	--no-data
  Do not write any table row information (that is, do not dump table contents). This is useful if you want to dump only theCREATE TABLE statement for the table (for example, to create an empty copy of the table by loading the dump file).

• --routines,-R

  Command-Line Format	--routines
  Include stored routines (procedures and functions) for the dumped databases in the output. This option requires the global SELECT privilege.
  The output generated by using --routines contains CREATE PROCEDURE andCREATE FUNCTION statements to create the routines.

• --skip-generated-invisible-primary-key

  Command-Line Format	--skip-generated-invisible-primary-key
  Type	Boolean
  Default Value	FALSE
  This option causes generated invisible primary keys to be excluded from the output. For more information, seeSection 15.1.20.11, “Generated Invisible Primary Keys”.

• --tables

  Command-Line Format	--tables
  Override the --databases or -B option. mysqldump regards all name arguments following the option as table names.

• --triggers

  Command-Line Format	--triggers
  Disabled by	skip-triggers
  Include triggers for each dumped table in the output. This option is enabled by default; disable it with--skip-triggers.
  To be able to dump a table's triggers, you must have theTRIGGER privilege for the table.
  Multiple triggers are permitted.mysqldump dumps triggers in activation order so that when the dump file is reloaded, triggers are created in the same activation order. However, if amysqldump dump file contains multiple triggers for a table that have the same trigger event and action time, an error occurs for attempts to load the dump file into an older server that does not support multiple triggers. (For a workaround, seeDowngrade Notes; you can convert triggers to be compatible with older servers.)

• --where='where_condition',-w '_`wherecondition`_'

  Command-Line Format	--where='where_condition'
  Dump only rows selected by the givenWHERE condition. Quotes around the condition are mandatory if it contains spaces or other characters that are special to your command interpreter.
  Examples:

--where="user='jimf'"  
-w"userid>1"  
-w"userid<1"  

Performance Options

The following options are the most relevant for the performance particularly of the restore operations. For large data sets, restore operation (processing the INSERT statements in the dump file) is the most time-consuming part. When it is urgent to restore data quickly, plan and test the performance of this stage in advance. For restore times measured in hours, you might prefer an alternative backup and restore solution, such asMySQL Enterprise Backup forInnoDB-only and mixed-use databases.

Performance is also affected by thetransactional options, primarily for the dump operation.

• --column-statistics

  Command-Line Format	--column-statistics
  Type	Boolean
  Default Value	OFF
  Add ANALYZE TABLE statements to the output to generate histogram statistics for dumped tables when the dump file is reloaded. This option is disabled by default because histogram generation for large tables can take a long time.

• --disable-keys,-K

  Command-Line Format	--disable-keys
  For each table, surround theINSERT statements with/*!40000 ALTER TABLE_`tblname`_ DISABLE KEYS */; and /*!40000 ALTER TABLE_`tblname`_ ENABLE KEYS */; statements. This makes loading the dump file faster because the indexes are created after all rows are inserted. This option is effective only for nonunique indexes of MyISAM tables.

• --extended-insert,-e

  Command-Line Format	--extended-insert
  Disabled by	skip-extended-insert
  Write INSERT statements using multiple-row syntax that includes severalVALUES lists. This results in a smaller dump file and speeds up inserts when the file is reloaded.

• --insert-ignore

  Command-Line Format	--insert-ignore
  Write INSERT IGNORE statements rather thanINSERT statements.

• --max-allowed-packet=value

  Command-Line Format	--max-allowed-packet=value
  Type	Numeric
  Default Value	25165824
  The maximum size of the buffer for client/server communication. The default is 24MB, the maximum is 1GB.
  Note
  The value of this option is specific tomysqldump and should not be confused with the MySQL server'smax_allowed_packet system variable; the server value cannot be exceeded by a single packet from mysqldump, regardless of any setting for the mysqldump option, even if the latter is larger.

• --mysqld-long-query-time=value

  Command-Line Format	--mysqld-long-query-time=value
  Type	Numeric
  Default Value	Server global setting
  Set the session value of thelong_query_time system variable. Use this option if you want to increase the time allowed for queries from mysqldump before they are logged to the slow query log file.mysqldump performs a full table scan, which means its queries can often exceed a globallong_query_time setting that is useful for regular queries. The default global setting is 10 seconds.
  You can use--mysqld-long-query-time to specify a session value from 0 (meaning that every query from mysqldump is logged to the slow query log) to 31536000, which is 365 days in seconds. Formysqldump’s option, you can only specify whole seconds. When you do not specify this option, the server’s global setting applies tomysqldump’s queries.

• --net-buffer-length=value

  Command-Line Format	--net-buffer-length=value
  Type	Numeric
  Default Value	16384
  The initial size of the buffer for client/server communication. When creating multiple-rowINSERT statements (as with the --extended-insert or--opt option),mysqldump creates rows up to--net-buffer-length bytes long. If you increase this variable, ensure that the MySQL server net_buffer_length system variable has a value at least this large.

• --network-timeout,-M

  Command-Line Format	--network-timeout[={0|1}]
  Type	Boolean
  Default Value	TRUE
  Enable large tables to be dumped by setting--max-allowed-packet to its maximum value and network read and write timeouts to a large value. This option is enabled by default. To disable it, use--skip-network-timeout.

• --opt

  Command-Line Format	--opt
  Disabled by	skip-opt
  This option, enabled by default, is shorthand for the combination of--add-drop-table --add-locks --create-options --disable-keys --extended-insert --lock-tables --quick --set-charset. It gives a fast dump operation and produces a dump file that can be reloaded into a MySQL server quickly.
  Because the --opt option is enabled by default, you only specify its converse, the--skip-opt to turn off several default settings. See the discussion ofmysqldump option groups for information about selectively enabling or disabling a subset of the options affected by--opt.

• --quick,-q

  Command-Line Format	--quick
  Disabled by	skip-quick
  This option is useful for dumping large tables. It forcesmysqldump to retrieve rows for a table from the server a row at a time rather than retrieving the entire row set and buffering it in memory before writing it out.

• --skip-opt

  Command-Line Format	--skip-opt
  See the description for the--opt option.

Transactional Options

The following options trade off the performance of the dump operation, against the reliability and consistency of the exported data.

• --add-locks

  Command-Line Format	--add-locks
  Surround each table dump with LOCK TABLES andUNLOCK TABLES statements. This results in faster inserts when the dump file is reloaded. SeeSection 10.2.5.1, “Optimizing INSERT Statements”.

• --flush-logs,-F

  Command-Line Format

  --flush-logs

  Flush the MySQL server log files before starting the dump. This option requires theRELOAD privilege. If you use this option in combination with the--all-databases option, the logs are flushed for each database dumped. The exception is when using--lock-all-tables,--source-data, or--single-transaction. In these cases, the logs are flushed only once, corresponding to the moment that all tables are locked byFLUSH TABLES WITH READ LOCK. If you want your dump and the log flush to happen at exactly the same moment, you should use--flush-logs together with--lock-all-tables,--source-data, or--single-transaction.

• --flush-privileges

  Command-Line Format	--flush-privileges
  Add a FLUSH PRIVILEGES statement to the dump output after dumping themysql database. This option should be used any time the dump contains the mysql database and any other database that depends on the data in the mysql database for proper restoration.
  Because the dump file contains a FLUSH PRIVILEGES statement, reloading the file requires privileges sufficient to execute that statement.

• --lock-all-tables,-x

  Command-Line Format	--lock-all-tables
  Lock all tables across all databases. This is achieved by acquiring a global read lock for the duration of the whole dump. This option automatically turns off--single-transaction and--lock-tables.

• --lock-tables,-l

  Command-Line Format	--lock-tables
  For each dumped database, lock all tables to be dumped before dumping them. The tables are locked withREAD LOCAL to permit concurrent inserts in the case of MyISAM tables. For transactional tables such as InnoDB,--single-transaction is a much better option than --lock-tables because it does not need to lock the tables at all.
  Because --lock-tables locks tables for each database separately, this option does not guarantee that the tables in the dump file are logically consistent between databases. Tables in different databases may be dumped in completely different states.
  Some options, such as--opt, automatically enable --lock-tables. If you want to override this, use --skip-lock-tables at the end of the option list.

• --no-autocommit

  Command-Line Format	--no-autocommit
  Enclose the INSERT statements for each dumped table within SET autocommit = 0 and COMMIT statements.

• --order-by-primary

  Command-Line Format	--order-by-primary
  Dump each table's rows sorted by its primary key, or by its first unique index, if such an index exists. This is useful when dumping a MyISAM table to be loaded into an InnoDB table, but makes the dump operation take considerably longer.

• --shared-memory-base-name=name

  Command-Line Format	--shared-memory-base-name=name
  Platform Specific	Windows
  On Windows, the shared-memory name to use for connections made using shared memory to a local server. The default value is MYSQL. The shared-memory name is case-sensitive.
  This option applies only if the server was started with theshared_memory system variable enabled to support shared-memory connections.

• --single-transaction

  Command-Line Format	--single-transaction
  This option sets the transaction isolation mode toREPEATABLE READ and sends a START TRANSACTION SQL statement to the server before dumping data. It is useful only with transactional tables such as InnoDB, because then it dumps the consistent state of the database at the time whenSTART TRANSACTION was issued without blocking any applications.
  The RELOAD orFLUSH_TABLES privilege is required with--single-transaction if both gtid_mode=ON and[gtid_purged=ON	AUTO](replication-options-gtids.html#sysvar%5Fgtid%5Fpurged).
  When using this option, you should keep in mind that onlyInnoDB tables are dumped in a consistent state. For example, any MyISAM orMEMORY tables dumped while using this option may still change state.
  While a--single-transaction dump is in process, to ensure a valid dump file (correct table contents and binary log coordinates), no other connection should use the following statements:ALTER TABLE,CREATE TABLE,DROP TABLE,RENAME TABLE,TRUNCATE TABLE. A consistent read is not isolated from those statements, so use of them on a table to be dumped can cause theSELECT that is performed bymysqldump to retrieve the table contents to obtain incorrect contents or fail.
  The --single-transaction option and the--lock-tables option are mutually exclusive because LOCK TABLES causes any pending transactions to be committed implicitly.
  To dump large tables, combine the--single-transaction option with the--quick option.

Option Groups

• The --opt option turns on several settings that work together to perform a fast dump operation. All of these settings are on by default, because--opt is on by default. Thus you rarely if ever specify --opt. Instead, you can turn these settings off as a group by specifying--skip-opt, then optionally re-enable certain settings by specifying the associated options later on the command line.
• The --compact option turns off several settings that control whether optional statements and comments appear in the output. Again, you can follow this option with other options that re-enable certain settings, or turn all the settings on by using the--skip-compact form.

When you selectively enable or disable the effect of a group option, order is important because options are processed first to last. For example,--disable-keys --lock-tables --skip-opt would not have the intended effect; it is the same as--skip-opt by itself.

Examples

To make a backup of an entire database:

mysqldump db_name > backup-file.sql

To load the dump file back into the server:

mysql db_name < backup-file.sql

Another way to reload the dump file:

mysql -e "source /path-to-backup/backup-file.sql" db_name

mysqldump is also very useful for populating databases by copying data from one MySQL server to another:

mysqldump --opt db_name | mysql --host=remote_host -C db_name

You can dump several databases with one command:

mysqldump --databases db_name1 [db_name2 ...] > my_databases.sql

To dump all databases, use the--all-databases option:

mysqldump --all-databases > all_databases.sql

For InnoDB tables,mysqldump provides a way of making an online backup:

mysqldump --all-databases --source-data --single-transaction > all_databases.sql

This backup acquires a global read lock on all tables (usingFLUSH TABLES WITH READ LOCK) at the beginning of the dump. As soon as this lock has been acquired, the binary log coordinates are read and the lock is released. If long updating statements are running when theFLUSH statement is issued, the MySQL server may get stalled until those statements finish. After that, the dump becomes lock free and does not disturb reads and writes on the tables. If the update statements that the MySQL server receives are short (in terms of execution time), the initial lock period should not be noticeable, even with many updates.

For point-in-time recovery (also known as“roll-forward,” when you need to restore an old backup and replay the changes that happened since that backup), it is often useful to rotate the binary log (seeSection 7.4.4, “The Binary Log”) or at least know the binary log coordinates to which the dump corresponds:

mysqldump --all-databases --source-data=2 > all_databases.sql

Or:

mysqldump --all-databases --flush-logs --source-data=2 > all_databases.sql

The --source-data option can be used simultaneously with the--single-transaction option, which provides a convenient way to make an online backup suitable for use prior to point-in-time recovery if tables are stored using the InnoDB storage engine.

For more information on making backups, seeSection 9.2, “Database Backup Methods”, andSection 9.3, “Example Backup and Recovery Strategy”.

• To select the effect of--opt except for some features, use the --skip option for each feature. To disable extended inserts and memory buffering, use --opt --skip-extended-insert --skip-quick. (Actually,--skip-extended-insert --skip-quick is sufficient because--opt is on by default.)
• To reverse --opt for all features except disabling of indexes and table locking, use--skip-opt --disable-keys --lock-tables.

Restrictions

mysqldump does not dump theperformance_schema or sys schema by default. To dump any of these, name them explicitly on the command line. You can also name them with the--databases option. Forperformance_schema, also use the--skip-lock-tables option.

mysqldump does not dump theINFORMATION_SCHEMA schema.

mysqldump does not dumpInnoDB CREATE TABLESPACE statements.

mysqldump does not dump the NDB Clusterndbinfo information database.

mysqldump includes statements to recreate thegeneral_log andslow_query_log tables for dumps of themysql database. Log table contents are not dumped.

If you encounter problems backing up views due to insufficient privileges, see Section 27.9, “Restrictions on Views” for a workaround.