The mysqldump client is a utility that performs logical backups, producing a set of SQL statements that can be run to reproduce the original schema objects, table data, or both. It dumps one or more MySQL database for backup or transfer to another SQL server. The mysqldump command can also generate output in CSV, other delimited text, or XML format.
mysqldump requires at least the
SELECT privilege for dumped
SHOW VIEW for dumped
TRIGGER for dumped
LOCK TABLES if the
--single-transaction 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 same privileges needed
to create each of the dumped objects by issuing
CREATE statements manually.
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
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 Section 10.1.4, “Connection Character Sets and Collations”), so the dump file
will not load correctly. To work around this issue, use the
--result-file option, which creates the
output in ASCII format:
mysqldump [options] --result-file=dump.sql
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:
If your tables are primarily
tables, or if you have a mix of
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
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 25.2, “MySQL Enterprise Backup Overview”.
If your tables are primarily
tables, consider using the mysqlhotcopy
instead, for better performance than
mysqldump of backup and restore
operations. See Section 4.6.10, “mysqlhotcopy — A Database Backup Program”.
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
--opt option (and hence
--quick) is enabled by
default, so to enable memory buffering, use
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 supports the following options,
which can be specified on the command line or in the
groups of an option file. For information about option files
used by MySQL programs, see Section 4.2.6, “Using Option Files”.
|--add-drop-database||Add a DROP DATABASE statement before each CREATE DATABASE statement|
|--add-drop-table||Add a DROP TABLE statement before each CREATE TABLE statement|
|--add-drop-trigger||Add a DROP TRIGGER statement before each CREATE TRIGGER statement|
|--add-locks||Surround each table dump with LOCK TABLES and UNLOCK TABLES statements|
|--all-databases||Dump all tables in all databases|
|--allow-keywords||Allow creation of column names that are keywords|
|--apply-slave-statements||Include STOP SLAVE prior to CHANGE MASTER statement and START SLAVE at end of output|
|--bind-address=ip_address||Use specified network interface to connect to MySQL Server||5.6.1|
|--comments||Add comments to the dump file|
|--compact||Produce more compact output|
|--compatible=name[,name,...]||Produce output that is more compatible with other database systems or with older MySQL servers|
|--complete-insert||Use complete INSERT statements that include column names|
|--create-options||Include all MySQL-specific table options in CREATE TABLE statements|
|--databases||Dump several databases|
|--debug[=debug_options]||Write a debugging log|
|--debug-check||Print debugging information when program exits|
|--debug-info||Print debugging information, memory, and CPU statistics when program exits|
|--default-auth=plugin||Authentication plugin to use|
|--default-character-set=charset_name||Specify default character set|
|--defaults-extra-file=file_name||Read option file in addition to usual option files|
|--defaults-file=file_name||Read only named option file|
|--defaults-group-suffix=str||Option group suffix value|
|--delayed-insert||Write INSERT DELAYED statements rather than INSERT statements|
|--delete-master-logs||On a master replication server, delete the binary logs after performing the dump operation|
|--disable-keys||For each table, surround the INSERT statements with statements to disable and enable keys|
|--dump-date||Include dump date as "Dump completed on" comment if --comments is given|
|--dump-slave[=value]||Include CHANGE MASTER statement that lists binary log coordinates of slave's master|
|--events||Dump events from the dumped databases|
|--extended-insert||Use multiple-row INSERT syntax that include several VALUES lists|
|--fields-enclosed-by=string||This option is used with the --tab option and has the same meaning as the corresponding clause for LOAD DATA INFILE|
|--fields-escaped-by||This option is used with the --tab option and has the same meaning as the corresponding clause for LOAD DATA INFILE|
|--fields-optionally-enclosed-by=string||This option is used with the --tab option and has the same meaning as the corresponding clause for LOAD DATA INFILE|
|--flush-logs||Flush the MySQL server log files before starting the dump|
|--flush-privileges||Emit a FLUSH PRIVILEGES statement after dumping the mysql database|
|--help||Display help message and exit|
|--hex-blob||Dump binary columns using hexadecimal notation (for example, 'abc' becomes 0x616263)|
|--host||Host to connect to (IP address or hostname)|
|--ignore-table=db_name.tbl_name||Do not dump the given table|
|--include-master-host-port||Include MASTER_HOST/MASTER_PORT options in CHANGE MASTER statement produced with --dump-slave|
|--insert-ignore||Write INSERT IGNORE statements rather than INSERT statements|
|--lock-all-tables||Lock all tables across all databases|
|--lock-tables||Lock all tables before dumping them|
|--log-error=file_name||Append warnings and errors to the named file|
|--login-path=name||Read login path options from .mylogin.cnf||5.6.6|
|--master-data[=value]||Write the binary log file name and position to the output|
|--max_allowed_packet=value||Maximum packet length to send to or receive from server|
|--net_buffer_length=value||Buffer size for TCP/IP and socket communication|
|--no-autocommit||Enclose the INSERT statements for each dumped table within SET autocommit = 0 and COMMIT statements|
|--no-create-db||This option suppresses the CREATE DATABASE statements|
|--no-create-info||Do not write CREATE TABLE statements that re-create each dumped table|
|--no-data||Do not dump table contents|
|--no-defaults||Read no option files|
|--no-set-names||Same as --skip-set-charset|
|--no-tablespaces||Do not write any CREATE LOGFILE GROUP or CREATE TABLESPACE statements in output|
|--opt||Shorthand for --add-drop-table --add-locks --create-options --disable-keys --extended-insert --lock-tables --quick --set-charset.|
|--order-by-primary||Dump each table's rows sorted by its primary key, or by its first unique index|
|--password[=password]||Password to use when connecting to server|
|--pipe||On Windows, connect to server using named pipe|
|--plugin-dir=path||Directory where plugins are installed|
|--port=port_num||TCP/IP port number to use for connection|
|--protocol=type||Connection protocol to use|
|--quick||Retrieve rows for a table from the server a row at a time|
|--quote-names||Quote identifiers within backtick characters|
|--replace||Write REPLACE statements rather than INSERT statements|
|--result-file=file||Direct output to a given file|
|--routines||Dump stored routines (procedures and functions) from the dumped databases|
|--secure-auth||Do not send passwords to the server in old (pre-4.1.1) format||5.6.17|
|--set-charset||Add SET NAMES default_character_set to output|
|--set-gtid-purged=value||Whether to add SET @@GLOBAL.GTID_PURGED to output||5.6.9|
|--shared-memory-base-name=name||The name of shared memory to use for shared-memory connections|
|--single-transaction||This option issues a BEGIN SQL statement before dumping data from the server|
|--skip-add-drop-table||Do not add a DROP TABLE statement before each CREATE TABLE statement|
|--skip-add-locks||Do not add locks|
|--skip-comments||Do not add comments to the dump file|
|--skip-compact||Do not produce more compact output|
|--skip-disable-keys||Do not disable keys|
|--skip-extended-insert||Turn off extended-insert|
|--skip-opt||Turn off the options set by --opt|
|--skip-quick||Do not retrieve rows for a table from the server a row at a time|
|--skip-quote-names||Do not quote identifiers|
|--skip-set-charset||Suppress the SET NAMES statement|
|--skip-triggers||Do not dump triggers|
|--skip-tz-utc||Turn off tz-utc|
|--socket=path||For connections to localhost, the Unix socket file to use|
|--ssl||Enable SSL for connection|
|--ssl-ca=file_name||Path of file that contains list of trusted SSL CAs|
|--ssl-capath=dir_name||Path of directory that contains trusted SSL CA certificates in PEM format|
|--ssl-cert=file_name||Path of file that contains X509 certificate in PEM format|
|--ssl-cipher=cipher_list||List of permitted ciphers to use for SSL encryption|
|--ssl-crl=file_name||Path of file that contains certificate revocation lists||5.6.3|
|--ssl-crlpath=dir_name||Path of directory that contains certificate revocation list files||5.6.3|
|--ssl-key=file_name||Path of file that contains X509 key in PEM format|
|--ssl-verify-server-cert||Verify server Common Name value in its certificate against host name used when connecting to server|
|--tab=path||Produce tab-separated data files|
|--tables||Override the --databases or -B option|
|--triggers||Dump triggers for each dumped table|
|--tz-utc||Add SET TIME_ZONE='+00:00' to the dump file|
|--user=user_name||MySQL user name to use when connecting to server|
|--version||Display version information and exit|
|--where='where_condition'||Dump only rows selected by the given WHERE condition|
|--xml||Produce XML output|
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.
On a computer having multiple network interfaces, use this option to select which interface to use for connecting to the MySQL server.
This option is supported beginning with MySQL 5.6.1.
Compress all information sent between the client and the server if both support compression.
A hint about the client-side authentication plugin to use. See Section 6.3.7, “Pluggable Authentication”.
Dump data from the MySQL server on the given host. The
default host is
Read options from the named login path in the
.mylogin.cnf login path file. A
“login path” is an option group that permits
only a limited set of options:
of a login path as a set of values that indicate the server
host and the credentials for authenticating with the server.
To create the login path file, use the
mysql_config_editor utility. See
Section 4.6.6, “mysql_config_editor — MySQL Configuration Utility”. This option was added
in MySQL 5.6.6.
The password to use when connecting to the server. If you
use the short option form (
cannot have a space between the option
and the password. If you omit the
password value following the
-p option on
the command line, mysqldump prompts for
Specifying a password on the command line should be considered insecure. See Section 188.8.131.52, “End-User Guidelines for Password Security”. You can use an option file to avoid giving the password on the command line.
On Windows, connect to the server using a named pipe. This option applies only if the server supports named-pipe connections.
The directory in which to look for plugins. It may be
necessary to specify this option if the
--default-auth option is
used to specify an authentication plugin but
mysqldump does not find it. See
Section 6.3.7, “Pluggable Authentication”.
The TCP/IP port number to use for the connection.
The connection protocol to use for connecting to the server. It is useful when the other connection parameters normally would cause a protocol to be used other than the one you want. For details on the permissible values, see Section 4.2.2, “Connecting to the MySQL Server”.
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. This option is enabled by default;
to disable it. This option was added in MySQL 5.6.17.
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 will be removed in a future MySQL release. For account upgrade instructions, see Section 184.108.40.206, “Migrating Away from Pre-4.1 Password Hashing and the mysql_old_password Plugin”.
For connections to
localhost, the Unix
socket file to use, or, on Windows, the name of the named
pipe to use.
The MySQL user name to use when connecting to the server.
You can also set the following variables by using
The maximum size of the buffer for client/server communication. The default is 24MB, the maximum is 1GB.
The initial size of the buffer for client/server
communication. When creating multiple-row
INSERT statements (as with
mysqldump creates rows up to
If you increase this variable, ensure that the
in the MySQL server is at least this large.
These options are used to control which option files to read.
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.
file_name is interpreted relative
to the current directory if given as a relative path name
rather than a full path name.
Use only the given option file. If the file does not exist
or is otherwise inaccessible, an error occurs.
file_name is interpreted relative
to the current directory if given as a relative path name
rather than a full path name.
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
[mysqldump] groups. If the
option is given, mysqldump also reads the
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
file, if it exists, is read in all cases. This permits
passwords to be specified in a safer way than on the command
line even when
--no-defaults is used.
.mylogin.cnf is created by the
mysql_config_editor utility. See
Section 4.6.6, “mysql_config_editor — MySQL Configuration Utility”.)
Print the program name and all options that it gets from option files.
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.
DROP DATABASE statement
statement. This option is typically used in conjunction with
--databases option because
CREATE DATABASE statements
are written unless one of those options is specified.
Adds to a table dump all SQL statements needed to create any
tablespaces used by an
table. This information is not otherwise included in the
output from mysqldump. This option is
currently relevant only to MySQL Cluster tables.
Do not write
statements that re-create each dumped table.
The following options print debugging information, encode debugging information in the dump file, or let the dump operation proceed regardless of potential problems.
Permit creation of column names that are keywords. This works by prefixing each column name with the table name.
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,
Write a debugging log. A typical
debug_options string is
The default value is
Print some debugging information when the program exits.
Print debugging information and memory and CPU usage statistics when the program exits.
-- Dump completed on
However, the date causes dump files taken at different times
to appear to be different, even if the data are otherwise
control whether the date is added to the comment. The
(include the date in the comment).
suppresses date printing.
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
mysqldump prints the error message, but
it also writes an SQL comment containing the view definition
to the dump output and continues executing.
Log warnings and errors by appending them to the named file. The default is to do no logging.
See the description for the
Verbose mode. Print more information about what the program does.
The following options display information about the mysqldump command itself.
The following options change how the mysqldump command represents character data with national language settings.
The directory where character sets are installed. See Section 10.5, “Character Set Configuration”.
Turns off the
--set-charset setting, the
same as specifying
to the output. This option is enabled by default. To
SET NAMES statement, use
The mysqldump command is frequently used to create an empty instance, or an instance including data, on a slave server in a replication configuration. The following options apply to dumping and restoring data on replication master and slave servers.
This option is similar to
--master-data except that
it is used to dump a replication slave server to produce a
dump file that can be used to set up another server as a
slave that has the same master 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 slave's master. These are the master
server coordinates from which the slave should start
--dump-slave causes the coordinates from
the master to be used rather than those of the dumped
server, as is done by the
--master-data option. In
addition, specfiying this option causes the
--master-data option to be overridden, if
used, and effectively ignored.
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
This option causes mysqldump to stop the slave SQL thread before the dump and restart it again after.
Use this option to dump a master replication server to
produce a dump file that can be used to set up another
server as a slave of the master. 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
master server coordinates from which the slave should start
replicating after you load the dump file into the slave.
If the option value is 2, the
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.
This option requires the
RELOAD privilege and the
binary log must be enabled.
--master-data option automatically
It also turns on
is specified, in which case, a global read lock is acquired
only for a short time at the beginning of the dump (see the
all cases, any action on logs happens at the exact moment of
It is also possible to set up a slave by dumping an existing
slave of the master, using the
--dump-slave option, which
--master-data and causes it to be
ignored if both options are used.
Prior to MySQL 5.6.4, this option was required for dumping the replication log tables (see Section 17.2.2, “Replication Relay and Status Logs”).
This option enables control over global transaction ID
(GTID) information written to the dump file, by indicating
whether to add a
@@global.gtid_purged statement to the output.
The following table shows the permitted option values. The
default value is
|Add no |
|Add a |
|Add a |
This option was added in MySQL 5.6.9.
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.
Produce output that is more compatible with other database
systems or with older MySQL servers. The value of
name can be
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 5.1.7, “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.
--compatible=oracle does not
map data types to Oracle types or use Oracle comment syntax.
This option requires a server version of 4.1.0 or higher. With older servers, it does nothing.
statements that include column names.
Include all MySQL-specific table options in the
CREATE TABLE statements.
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
Direct output to a given file. This option should be used on
Windows to prevent newline
\n” characters from being
converted to “
return/newline sequences. The result file is created and its
previous contents overwritten, even if an error occurs while
generating the dump.
Produce tab-separated text-format data files. For each
dumped table, mysqldump creates a
file that contains the
TABLE statement that creates the table, and the
server writes a
file that contains its data. The option value is the
directory in which to write the files.
This option should be used only when
mysqldump is run on the same machine as
the mysqld server. You must have the
FILE privilege, and the
server must have permission to write files in the
directory that you specify.
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
Column values are converted to the character set specified
This option enables
columns to be dumped and reloaded between servers in
different time zones. mysqldump sets its
connection time zone to UTC and adds
TIME_ZONE='+00:00' to the dump file. Without this
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.
enabled by default. To disable it, use
Write dump output as well-formed XML.
'NULL', and Empty Values: For
a column named
NULL value, an empty string, and the
'NULL' are distinguished
from one another in the output generated by this option as
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>
Prior to MySQL 5.6.5, this option prevented the
--routines option from
working correctly—that is, no stored routines,
triggers, or events could be dumped in XML format. (Bug
#11760384, Bug #52792)
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
Dump all tables in all databases. This is the same as using
--databases option and
naming all the databases on the command line.
Prior to MySQL 5.6.4, the
slave_relay_log_info tables (see
Section 17.2.2, “Replication Relay and Status Logs”) were not included by this
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.
statements are included in the output before each new
Include Event Scheduler events for the dumped databases in
the output. This option requires the
EVENT privileges for those
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.
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).
Include stored routines (procedures and functions) for the
dumped databases in the output. Use of this option requires
SELECT privilege for the
mysql.proc table. The output generated by
CREATE PROCEDURE and
CREATE FUNCTION statements to
re-create the routines. However, these statements do not
include attributes such as the routine creation and
modification timestamps. This means that when the routines
are reloaded, they will be created with the timestamps equal
to the reload time.
If you require routines to be re-created with their original
timestamp attributes, do not use
--routines. Instead, dump and reload the
contents of the
directly, using a MySQL account that has appropriate
privileges for the
Prior to MySQL 5.6.5, this option had no effect when used
together with the
option. (Bug #11760384, Bug #52792)
Include triggers for each dumped table in the output. This
option is enabled by default; disable it with
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.
--where="user='jimf'" -w"userid>1" -w"userid<1"
The following options are the most relevant for the performance
particularly of the restore operations. For large data sets,
restore operation (processing the
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
mixed-use databases, or mysqlhotcopy for
Performance is also affected by the transactional options, primarily for the dump operation.
As of MySQL 5.6.6,
DELAYED inserts are
deprecated, so this option will be removed in a future
For each table, surround the
INSERT statements with
/*!40000 ALTER TABLE
tbl_name DISABLE KEYS
/*!40000 ALTER TABLE
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
tbl_name ENABLE KEYS
syntax that include several
This results in a smaller dump file and speeds up inserts
when the file is reloaded.
This option, enabled by default, is shorthand for the
--set-charset. It gives a
fast dump operation and produces a dump file that can be
reloaded into a MySQL server quickly.
--opt option is enabled by
default, you only specify its converse, the
--skip-opt to turn off
several default settings. See the discussion of
option groups for information about selectively
enabling or disabling a subset of the options affected by
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.
See the description for the
The following options trade off the performance of the dump operation, against the reliability and consistency of the exported data.
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
the logs are flushed for each database
dumped. The exception is when using
this case, the logs are flushed only once, corresponding to
the moment that all tables are locked. If you want your dump
and the log flush to happen at exactly the same moment, you
--flush-logs together with
PRIVILEGES statement to the dump output after
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
database for proper restoration.
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
--single-transaction is a
much better option than
because it does not need to lock the tables at all.
--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
--lock-tables. If you want to
override this, use
the end of the option list.
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
InnoDB table, but makes the dump
operation take considerably longer.
On Windows, the shared-memory name to use, for connections
made using shared memory to a local server. The default
MYSQL. The shared-memory name is
The server must be started with the
--shared-memory option to
enable shared-memory connections.
This option sets the transaction isolation mode to
REPEATABLE READ and sends a
TRANSACTION SQL statement to the server before
dumping data. It is useful only with transactional tables
InnoDB, because then it dumps the
consistent state of the database at the time when
TRANSACTION was issued without blocking any
When using this option, you should keep in mind that only
InnoDB tables are dumped in a consistent
state. For example, any
MEMORY tables dumped while using this
option may still change state.
is in process, to ensure a valid dump file (correct table
contents and binary log coordinates), no other connection
should use the following statements:
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.
To dump large tables, combine the
--single-transaction option with 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
--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.
--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
When you selectively enable or disable the effect of a group
option, order is important because options are processed first
to last. For example,
--skip-opt would not have the
intended effect; it is the same as
--skip-opt by itself.
To make a backup of an entire database:
To load the dump file back into the server:
Another way to reload the dump file:
mysql -e "source
mysqldump is also very useful for populating databases by copying data from one MySQL server to another:
db_name| mysql --host=
You can dump several databases with one command:
db_name2...] > my_databases.sql
To dump all databases, use the
mysqldump --all-databases > all_databases.sql
mysqldump provides a way of making an online
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
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 5.2.4, “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
mysqldump --all-databases --flush-logs --master-data=2
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”.
To select the effect of
--opt except for some
features, use the
--skip option for each
feature. To disable extended inserts and memory buffering,
is sufficient because
--opt is on by default.)
mysqldump does not dump the
performance_schema database by default. To
dump either of these, name it explicitly on the command line.
You can also name it with the
--databases option. Also, use
Before MySQL 5.6.6, mysqldump does not dump
slow_query_log tables for dumps of the
mysql database. As of 5.6.6, the dump
includes statements to recreate those tables so that they are
not missing after reloading the dump file. Log table contents
are not dumped.
If you encounter problems backing up views due to insufficient privileges, see Section D.5, “Restrictions on Views” for a workaround.