mysqldump - a database backup program
mysqldump [options] [db_name [tbl_name ...]]
MYSQLDUMP(1) MySQL Database System MYSQLDUMP(1)
NAME
mysqldump - a database backup program
SYNOPSIS
mysqldump [options] [db_name [tbl_name ...]]
DESCRIPTION
The mysqldump client utility performs logical 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.
o Performance and Scalability Considerations
o Invocation Syntax
o Option Syntax - Alphabetical Summary
o Connection Options
o Option-File Options
o DDL Options
o Debug Options
o Help Options
o Internationalization Options
o Replication Options
o Format Options
o Filtering Options
o Performance Options
o Transactional Options
o Option Groups
o Examples
o Restrictions
mysqldump requires at least the SELECT privilege for dumped tables,
SHOW VIEW for dumped views, TRIGGER for dumped triggers, LOCK TABLES if
the --single-transaction option is not used, and (as of MySQL 5.7.31)
PROCESS if the --no-tablespaces option is not used. 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 appropriate CREATE
privileges for objects created by those statements.
mysqldump output can include ALTER 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, the ALTER 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 (see
the section called "Impermissible 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, a physical backup is more
appropriate, to copy the data files in their original format that can
be restored quickly:
o If your tables are primarily InnoDB tables, or if you have a mix of
InnoDB and MyISAM tables, consider using the mysqlbackup command of
the MySQL Enterprise Backup product. (Available as part of the
Enterprise subscription.) It provides the best performance for
InnoDB backups with minimal disruption; it can also back up tables
from MyISAM and other storage engines; and it provides a number of
convenient options to accommodate different backup scenarios. See
Section 28.2, "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 of mysqldump 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 7.4, "Using
mysqldump for Backups". Invocation Syntax
There are in general three ways to use mysqldump--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 db_name, or
use the --databases or --all-databases option.
To see a list of the options your version of mysqldump supports, issue
the command mysqldump --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 4.2.2.2, "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.
o --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.
o --compress, -C Compress all information sent between the client and
the server if possible. See Section 4.2.6, "Connection Compression
Control".
o --default-auth=plugin A hint about which client-side authentication
plugin to use. See Section 6.2.13, "Pluggable Authentication".
o --enable-cleartext-plugin Enable the mysql_clear_password cleartext
authentication plugin. (See Section 6.4.1.6, "Client-Side Cleartext
Pluggable Authentication".)
This option was added in MySQL 5.7.10.
o --get-server-public-key Request from the server the public key
required for RSA key pair-based password exchange. This option
applies to clients that authenticate with the caching_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 the caching_sha2_password plugin, see
Section 6.4.1.4, "Caching SHA-2 Pluggable Authentication".
The --get-server-public-key option was added in MySQL 5.7.23.
o --host=host_name, -h host_name Dump data from the MySQL server on
the given host. The default host is localhost.
o --login-path=name 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 the mysql_config_editor utility. See
mysql_config_editor(1).
For additional information about this and other option-file
options, see Section 4.2.2.3, "Command-Line Options that Affect
Option-File Handling".
o --password[=password], -p[password] 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. See Section 6.1.2.1, "End-User Guidelines for Password
Security".
To explicitly specify that there is no password and that mysqldump
should not prompt for one, use the --skip-password option.
o --pipe, -W On Windows, connect to the server using a named pipe.
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 the
named_pipe_full_access_group system variable.
o --plugin-dir=dir_name The directory in which to look for plugins.
Specify this option if the --default-auth option is used to specify
an authentication plugin but mysqldump does not find it. See
Section 6.2.13, "Pluggable Authentication".
o --port=port_num, -P port_num For TCP/IP connections, the port
number to use.
o --protocol={TCP|SOCKET|PIPE|MEMORY} 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, see
Section 4.2.5, "Connection Transport Protocols".
o --secure-auth Do not send passwords to the server in old (pre-4.1)
format. This prevents connections except for servers that use the
newer password format.
As of MySQL 5.7.5, this option is deprecated; expect it to be
removed in a future MySQL release. It is always enabled and
attempting to disable it (--skip-secure-auth, --secure-auth=0)
produces an error. Before MySQL 5.7.5, this option is enabled by
default but can be disabled.
Note
Passwords that use the pre-4.1 hashing method are less secure
than passwords that use the native password hashing method and
should be avoided. Pre-4.1 passwords are deprecated and support
for them was removed in MySQL 5.7.5. For account upgrade
instructions, see Section 6.4.1.3, "Migrating Away from Pre-4.1
Password Hashing and the mysql_old_password Plugin".
o --server-public-key-path=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 the sha256_password or
caching_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, this option applies only if MySQL was built
using OpenSSL.
For information about the sha256_password and caching_sha2_password
plugins, see Section 6.4.1.5, "SHA-256 Pluggable Authentication",
and Section 6.4.1.4, "Caching SHA-2 Pluggable Authentication".
The --server-public-key-path option was added in MySQL 5.7.23.
o --skip-mysql-schema Do not drop the mysql schema when the dump file
is restored. By default, the schema is dropped.
This option was added in MySQL 5.7.36.
o --socket=path, -S path 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 the
named_pipe_full_access_group system variable.
o --ssl* Options that begin with --ssl specify whether to connect to
the server using encryption and indicate where to find SSL keys and
certificates. See the section called "Command Options for Encrypted
Connections".
o --tls-version=protocol_list 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, see Section 6.3.2, "Encrypted Connection TLS Protocols and
Ciphers".
This option was added in MySQL 5.7.10.
o --user=user_name, -u user_name The user name of the MySQL account
to use for connecting to the server.
Option-File Options
These options are used to control which option files to read.
o --defaults-extra-file=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 file_name 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 4.2.2.3, "Command-Line Options that Affect
Option-File Handling".
o --defaults-file=file_name Use only the given option file. If the
file does not exist or is otherwise inaccessible, an error occurs.
If file_name 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 4.2.2.3, "Command-Line Options that Affect
Option-File Handling".
o --defaults-group-suffix=str 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 4.2.2.3, "Command-Line Options that Affect
Option-File Handling".
o --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 the mysql_config_editor utility. See
mysql_config_editor(1).
For additional information about this and other option-file
options, see Section 4.2.2.3, "Command-Line Options that Affect
Option-File Handling".
o --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 4.2.2.3, "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.
o --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.
o --add-drop-table Write a DROP TABLE statement before each CREATE
TABLE statement.
o --add-drop-trigger Write a DROP TRIGGER statement before each
CREATE TRIGGER statement.
o --all-tablespaces, -Y 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, which
are not supported in MySQL 5.7.
o --no-create-db, -n Suppress the CREATE DATABASE statements that are
otherwise included in the output if the --databases or
--all-databases option is given.
o --no-create-info, -t Do not write CREATE TABLE statements that
create each dumped table.
Note
This option does not exclude statements creating log file
groups or tablespaces from mysqldump output; however, you can
use the --no-tablespaces option for this purpose.
o --no-tablespaces, -y This option suppresses all CREATE LOGFILE
GROUP and CREATE TABLESPACE statements in the output of mysqldump.
o --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.
o --allow-keywords Permit creation of column names that are keywords.
This works by prefixing each column name with the table name.
o --comments, -i 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.
o --debug[=debug_options], -# [debug_options] Write a debugging log.
A typical debug_options string is d:t:o,file_name. The default
value is d:t:o,/tmp/mysqldump.trace.
This option is available only if MySQL was built using WITH_DEBUG.
MySQL release binaries provided by Oracle are not built using this
option.
o --debug-check Print some debugging information when the program
exits.
This option is available only if MySQL was built using WITH_DEBUG.
MySQL release binaries provided by Oracle are not built using this
option.
o --debug-info Print debugging information and memory and CPU usage
statistics when the program exits.
This option is available only if MySQL was built using WITH_DEBUG.
MySQL release binaries provided by Oracle are not built using this
option.
o --dump-date 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.
o --force, -f Ignore all errors; continue even if an SQL error occurs
during a table dump.
One use for this option is to cause mysqldump 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.
o --log-error=file_name Log warnings and errors by appending them to
the named file. The default is to do no logging.
o --skip-comments See the description for the --comments option.
o --verbose, -v Verbose mode. Print more information about what the
program does.
Help Options
The following options display information about the mysqldump command
itself.
o --help, -? Display a help message and exit.
o --version, -V Display version information and exit.
Internationalization Options
The following options change how the mysqldump command represents
character data with national language settings.
o --character-sets-dir=dir_name The directory where character sets
are installed. See Section 10.15, "Character Set Configuration".
o --default-character-set=charset_name Use charset_name as the
default character set. See Section 10.15, "Character Set
Configuration". If no character set is specified, mysqldump uses
utf8.
o --no-set-names, -N Turns off the --set-charset setting, the same as
specifying --skip-set-charset.
o --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 and replica servers.
o --apply-slave-statements For a replica dump produced with the
--dump-slave option, add a STOP SLAVE statement before the CHANGE
MASTER TO statement and a START SLAVE statement at the end of the
output.
o --delete-master-logs On a source replication server, delete the
binary logs by sending a PURGE BINARY LOGS statement to the server
after performing the dump operation. This option requires the
RELOAD privilege as well as privileges sufficient to execute that
statement. This option automatically enables --master-data.
o --dump-slave[=value] This option is similar to --master-data except
that it is used to dump a replication 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. It causes the dump
output to include a CHANGE MASTER TO statement that indicates the
binary log coordinates (file name and position) of the dumped
replica's source. The CHANGE MASTER TO statement reads the values
of Relay_Master_Log_File and Exec_Master_Log_Pos from the SHOW
SLAVE STATUS output and uses them for MASTER_LOG_FILE and
MASTER_LOG_POS respectively. These are the source server
coordinates from which the replica should start replicating.
Note
Inconsistencies in the sequence of transactions from the relay
log which have been executed can cause the wrong position to be
used. See Section 16.4.1.32, "Replication and Transaction
Inconsistencies" for more information.
--dump-slave causes the coordinates from the source to be used
rather than those of the dumped server, as is done by the
--master-data option. In addition, specifiying this option causes
the --master-data option to be overridden, if used, and effectively
ignored.
Warning
This option should not be used if the server where the dump is
going to be applied uses gtid_mode=ON and
MASTER_AUTOPOSITION=1.
The option value is handled the same way as for --master-data
(setting no value or 1 causes a CHANGE MASTER TO statement to be
written to the dump, setting 2 causes the statement to be written
but encased in SQL comments) and has the same effect as
--master-data in terms of enabling or disabling other options and
in how locking is handled.
This option causes mysqldump to stop the replica SQL thread before
the dump and restart it again after.
--dump-slave sends a SHOW SLAVE STATUS statement to the server to
obtain information, so it requires privileges sufficient to execute
that statement.
In conjunction with --dump-slave, the --apply-slave-statements and
--include-master-host-port options can also be used.
o --include-master-host-port For the CHANGE MASTER TO statement in a
replica dump produced with the --dump-slave option, add MASTER_HOST
and MASTER_PORT options for the host name and TCP/IP port number of
the replica's source.
o --master-data[=value] Use this option to dump a source replication
server to produce a dump file that can be used to set up another
server as a replica of the source. It causes the dump output to
include a CHANGE MASTER TO statement that indicates the binary log
coordinates (file name and position) of the dumped server. These
are the 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 MASTER 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.
--master-data sends a SHOW MASTER STATUS statement to the server to
obtain information, so it requires privileges sufficient to execute
that statement. This option also requires the RELOAD privilege and
the binary log must be enabled.
The --master-data option automatically turns off --lock-tables. It
also turns 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-slave option, which
overrides --master-data and causes it to be ignored if both options
are used.
o --set-gtid-purged=value This option enables control over global
transaction ID (GTID) information written to the dump file, by
indicating whether to add a SET @@GLOBAL.gtid_purged statement to
the output. This option may also cause a statement to be written to
the output that disables binary logging while the dump file is
being reloaded.
The following table shows the permitted option values. The default
value is AUTO.
+------+----------------------------+
|Value | Meaning |
+------+----------------------------+
|OFF | Add no SET statement to |
| | the output. |
+------+----------------------------+
|ON | Add a SET statement to the |
| | output. An error occurs if |
| | GTIDs |
| | are not enabled on the |
| | server. |
+------+----------------------------+
|AUTO | Add a SET statement to the |
| | output if GTIDs are |
| | enabled |
| | on the server. |
+------+----------------------------+
A partial dump from a server that is using GTID-based replication
requires the --set-gtid-purged={ON|OFF} option to be specified. Use
ON if the intention is to deploy a new replication replica using
only some of the data from the dumped server. Use OFF if the
intention is to repair a table by copying it within a topology. Use
OFF if the intention is to copy a table between replication
topologies that are disjoint and for them to remain so.
The --set-gtid-purged option has the following effect on binary
logging when the dump file is reloaded:
o --set-gtid-purged=OFF: SET @@SESSION.SQL_LOG_BIN=0; is not
added to the output.
o --set-gtid-purged=ON: SET @@SESSION.SQL_LOG_BIN=0; is added to
the output.
o --set-gtid-purged=AUTO: SET @@SESSION.SQL_LOG_BIN=0; is added
to the output if GTIDs are enabled on the server you are
backing up (that is, if AUTO evaluates to ON).
Note
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. Also be aware that loading a dump file from
a server with GTIDs enabled, into another server with GTIDs
enabled, causes different transaction identifiers to be
generated.
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.
o --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.
o --compatible=name Produce output that is more compatible with other
database systems or with older MySQL servers. The value of name can
be ansi, mysql323, mysql40, postgresql, oracle, mssql, db2, maxdb,
no_key_options, no_table_options, or no_field_options. To use
several values, separate them by commas. These values have the same
meaning as the corresponding options for setting the server SQL
mode. See Section 5.1.10, "Server SQL Modes".
This option does not guarantee compatibility with other servers. It
only enables those SQL mode values that are currently available for
making dump output more compatible. For example,
--compatible=oracle does not map data types to Oracle types or use
Oracle comment syntax.
o --complete-insert, -c Use complete INSERT statements that include
column names.
o --create-options Include all MySQL-specific table options in the
CREATE TABLE statements.
o --fields-terminated-by=..., --fields-enclosed-by=...,
--fields-optionally-enclosed-by=..., --fields-escaped-by=... These
options are used with the --tab option and have the same meaning as
the corresponding FIELDS clauses for LOAD DATA. See Section 13.2.6,
"LOAD DATA Statement".
o --hex-blob Dump binary columns using hexadecimal notation (for
example, 'abc' becomes 0x616263). The affected data types are
BINARY, VARBINARY, BLOB types, BIT, all spatial data types, and
other non-binary data types when used with the binary character
set.
o --lines-terminated-by=... This option is used with the --tab
option and has the same meaning as the corresponding LINES clause
for LOAD DATA. See Section 13.2.6, "LOAD DATA Statement".
o --quote-names, -Q Quote identifiers (such as database, table, and
column names) within ` characters. If the ANSI_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.
o --result-file=file_name, -r 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.
o --tab=dir_name, -T dir_name Produce tab-separated text-format data
files. For each dumped table, mysqldump creates a tbl_name.sql file
that contains the CREATE TABLE statement that creates the table,
and the server writes a tbl_name.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 when mysqldump 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 the FILE privilege. Because mysqldump 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.
o --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.
o --xml, -X Write dump output as well-formed XML.
NULL, 'NULL', and Empty Values: For a column named column_name, the
NULL 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) | |
| | <field |
| | name="column_name" |
| | xsi:nil="true" |
| | /> |
+---------------------+--------------------------------------------+
| | |
| | <field |
| | name="column_name"></field> |
+---------------------+--------------------------------------------+
| | |
| | <field |
| | name="column_name">NULL</field> |
+---------------------+--------------------------------------------+
The output from the mysql client when run using the --xml option
also follows the preceding rules. (See the section called "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.
o --all-databases, -A Dump all tables in all databases. This is the
same as using the --databases option and naming all the databases
on the command line.
o --databases, -B 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 the INFORMATION_SCHEMA and
performance_schema databases, which normally are not dumped even
with the --all-databases option. (Also use the --skip-lock-tables
option.)
o --events, -E Include Event Scheduler events for the dumped
databases in the output. This option requires the EVENT privileges
for those databases.
The output generated by using --events contains CREATE EVENT
statements to create the events. However, these statements do not
include attributes such as the event creation and modification
timestamps, so when the events are reloaded, they are created with
timestamps equal to the reload time.
If you require events to be created with their original timestamp
attributes, do not use --events. Instead, dump and reload the
contents of the mysql.event table directly, using a MySQL account
that has appropriate privileges for the mysql database.
o --ignore-error=error[,error]... 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.
o --ignore-table=db_name.tbl_name 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.
o --no-data, -d Do not write any table row information (that is, do
not dump table contents). This is useful if you want to dump only
the CREATE TABLE statement for the table (for example, to create an
empty copy of the table by loading the dump file).
o --routines, -R Include stored routines (procedures and functions)
for the dumped databases in the output. This option requires the
SELECT privilege for the mysql.proc table.
The output generated by using --routines contains CREATE PROCEDURE
and CREATE FUNCTION statements to create the routines. However,
these statements do not include attributes such as the routine
creation and modification timestamps, so when the routines are
reloaded, they are created with timestamps equal to the reload
time.
If you require routines to be created with their original timestamp
attributes, do not use --routines. Instead, dump and reload the
contents of the mysql.proc table directly, using a MySQL account
that has appropriate privileges for the mysql database.
o --tables Override the --databases or -B option. mysqldump regards
all name arguments following the option as table names.
o --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 the TRIGGER
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 a mysqldump
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, see Section 2.12.3, "Downgrade Notes";
you can convert triggers to be compatible with older servers.)
o --where='where_condition', -w 'where_condition' Dump only rows
selected by the given WHERE 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 as MySQL Enterprise Backup for InnoDB-only and
mixed-use databases.
Performance is also affected by the transactional options, primarily
for the dump operation.
o --disable-keys, -K For each table, surround the INSERT statements
with /*!40000 ALTER TABLE tbl_name DISABLE KEYS */; and /*!40000
ALTER TABLE tbl_name 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.
o --extended-insert, -e Write INSERT statements using multiple-row
syntax that includes several VALUES lists. This results in a
smaller dump file and speeds up inserts when the file is reloaded.
o --insert-ignore Write INSERT IGNORE statements rather than INSERT
statements.
o --max-allowed-packet=value The maximum size of the buffer for
client/server communication. The default is 24MB, the maximum is
1GB.
o --net-buffer-length=value The initial size of the buffer for
client/server communication. When creating multiple-row INSERT
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.
o --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 of mysqldump option groups for information about
selectively enabling or disabling a subset of the options affected
by --opt.
o --quick, -q This option is useful for dumping large tables. It
forces mysqldump 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.
o --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.
o --add-locks Surround each table dump with LOCK TABLES and UNLOCK
TABLES statements. This results in faster inserts when the dump
file is reloaded. See Section 8.2.4.1, "Optimizing INSERT
Statements".
o --flush-logs, -F Flush the MySQL server log files before starting
the dump. This option requires the RELOAD 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, --master-data, or --single-transaction: In
this case, the logs are flushed only once, corresponding to the
moment that all tables are locked by FLUSH 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, --master-data, or --single-transaction.
o --flush-privileges Add a FLUSH PRIVILEGES statement to the dump
output after dumping the mysql 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.
Note
For upgrades to MySQL 5.7 or higher from older versions, do not
use --flush-privileges. For upgrade instructions in this case,
see Section 2.11.3, "Changes in MySQL 5.7".
o --lock-all-tables, -x 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.
o --lock-tables, -l For each dumped database, lock all tables to be
dumped before dumping them. The tables are locked with READ 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.
o --no-autocommit Enclose the INSERT statements for each dumped table
within SET autocommit = 0 and COMMIT statements.
o --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.
o --shared-memory-base-name=name 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 the
shared_memory system variable enabled to support shared-memory
connections.
o --single-transaction This option sets the transaction isolation
mode to REPEATABLE 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 when START TRANSACTION
was issued without blocking any applications.
When using this option, you should keep in mind that only InnoDB
tables are dumped in a consistent state. For example, any MyISAM or
MEMORY 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 the SELECT that is performed
by mysqldump 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
o 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, the optionally re-enable certain settings
by specifying the associated options later on the command line.
o 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 --master-data --single-transaction > all_databases.sql
This backup acquires a global read lock on all tables (using FLUSH
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 the
FLUSH 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 (see
Section 5.4.4, "The Binary Log") or at least know the binary log
coordinates to which the dump corresponds:
mysqldump --all-databases --master-data=2 > all_databases.sql
Or:
mysqldump --all-databases --flush-logs --master-data=2 > all_databases.sql
The --master-data and --single-transaction options can be used
simultaneously, 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, see Section 7.2, "Database
Backup Methods", and Section 7.3, "Example Backup and Recovery
Strategy".
o 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.)
o To reverse --opt for all features except index disabling and table
locking, use --skip-opt --disable-keys --lock-tables.
Restrictions
mysqldump does not dump the INFORMATION_SCHEMA, performance_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.
For INFORMATION_SCHEMA and performance_schema, also use the
--skip-lock-tables option.
mysqldump does not dump the NDB Cluster ndbinfo information database.
mysqldump does not dump InnoDB CREATE TABLESPACE statements.
It is not recommended to restore from a dump made using mysqldump to a
MySQL 5.6.9 or earlier server that has GTIDs enabled. See
Section 16.1.3.6, "Restrictions on Replication with GTIDs".
mysqldump includes statements to recreate the general_log and
slow_query_log tables for dumps of the mysql database. Log table
contents are not dumped.
If you encounter problems backing up views due to insufficient
privileges, see Section 23.9, "Restrictions on Views" for a workaround.
COPYRIGHT
Copyright (C) 1997, 2022, Oracle and/or its affiliates.
This documentation is free software; you can redistribute it and/or
modify it only under the terms of the GNU General Public License as
published by the Free Software Foundation; version 2 of the License.
This documentation is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License along
with the program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA or see
http://www.gnu.org/licenses/.
ATTRIBUTES
See attributes(7) for descriptions of the following attributes:
+---------------+--------------------------+
|ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+---------------+--------------------------+
|Availability | database/mysql-57/client |
+---------------+--------------------------+
|Stability | Uncommitted |
+---------------+--------------------------+
SEE ALSO
For more information, please refer to the MySQL Reference Manual, which
may already be installed locally and which is also available online at
http://dev.mysql.com/doc/.
AUTHOR
Oracle Corporation (http://dev.mysql.com/).
NOTES
Source code for open source software components in Oracle Solaris can
be found at https://www.oracle.com/downloads/opensource/solaris-source-
code-downloads.html.
This software was built from source available at
https://github.com/oracle/solaris-userland. The original community
source was downloaded from
https://dev.mysql.com/get/Downloads/MySQL-5.7/mysql-
boost-5.7.38.tar.gz.
Further information about this software can be found on the open source
community website at https://dev.mysql.com/.
MySQL 5.7 03/21/2022 MYSQLDUMP(1)