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MYSQLDUMP(1) | MySQL Database System | MYSQLDUMP(1) |
NAME¶
mysqldump - a database backup programSYNOPSIS¶
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.•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 the SELECT privilege for dumped tables, SHOW
VIEW for dumped views, TRIGGER for dumped triggers, and 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 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.
shell> mysqldump [options] > dump.sql
shell> mysqldump [options] --result-file=dump.sql
•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 25.2, “MySQL
Enterprise Backup Overview”.
•If your tables are primarily MyISAM tables,
consider using the mysqlhotcopy instead, for better performance than
mysqldump of backup and restore operations. See
mysqlhotcopy(1).
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.PP 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:
shell> mysqldump [options] db_name [tbl_name ...] shell> mysqldump [options] --databases db_name ... shell> mysqldump [options] --all-databases
•--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.
This option is supported beginning with MySQL 5.6.1.
•--compress, -C
Compress all information sent between the client and the server if both support
compression.
•--default-auth=plugin
A hint about the client-side authentication plugin to use. See
Section 6.3.7, “Pluggable Authentication”.
•--enable-cleartext-plugin
Enable the mysql_clear_password cleartext authentication plugin. (See
Section 6.4.1.7, “The Cleartext Client-Side Authentication
Plugin”.)
This option was added in MySQL 5.6.28.
•--host=host_name, -h
host_name
Dump data from the MySQL server on the given host. The default host is
localhost.
•--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). This option was added in MySQL
5.6.6.
•--password[=password],
-p[password]
The password to use when connecting to the server. If you use the short option
form ( -p), you cannot have a space between the option and the
password. If you omit the password value following the
--password or -p option on the command line, mysqldump
prompts for one.
Specifying a password on the command line should be considered insecure. See
Section 6.1.2.1, “End-User Guidelines for Password
Security”. You can use an option file to avoid giving the password on
the command line.
•--pipe, -W
On Windows, connect to the server using a named pipe. This option applies only
if the server supports named-pipe connections.
•--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 6.3.7, “Pluggable
Authentication”.
•--port=port_num, -P
port_num
The TCP/IP port number to use for the connection.
•--protocol={TCP|SOCKET|PIPE|MEMORY}
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”.
•--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. This option
is enabled by default; use --skip-secure-auth to disable it. This
option was added in MySQL 5.6.17.
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 will be removed in a future
MySQL release. For account upgrade instructions, see Section 6.4.1.3,
“Migrating Away from Pre-4.1 Password Hashing and the
mysql_old_password Plugin”.
•--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.
•--ssl*
Options that begin with --ssl specify whether to connect to the server
using SSL and indicate where to find SSL keys and certificates. See
Section 6.3.9.5, “Command Options for Secure
Connections”.
•--user=user_name, -u
user_name
The MySQL user name to use when connecting to the server.
You can also set the following variables by using
--var_name =value syntax:
•max_allowed_packet
The maximum size of the buffer for client/server communication. The default is
24MB, the maximum is 1GB.
•net_buffer_length
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.
Option-File Options.PP These options are used to control which option files to
read.
•--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. file_name is interpreted relative to the current directory if
given as a relative path name rather than a full path name.
•--defaults-file=file_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.
•--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 the --defaults-group-suffix=_other
option is given, mysqldump also reads the [client_other] and
[mysqldump_other] groups.
•--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, 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 mysql_config_editor(1).)
•--print-defaults
Print the program name and all options that it gets from option files.
DDL Options.PP 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
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.
•--add-drop-table
Write a DROP TABLE statement before each CREATE TABLE statement.
•--add-drop-trigger
Write a DROP TRIGGER statement before each CREATE TRIGGER statement.
•--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 MySQL Cluster
tables.
•--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.
•--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.
•--no-tablespaces, -y
This option suppresses all CREATE LOGFILE GROUP and CREATE TABLESPACE statements
in the output of mysqldump.
•--replace
Write REPLACE statements rather than INSERT statements.
Debug Options.PP 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
Permit creation of column names that are keywords. This works by prefixing each
column name with the table name.
•--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.
•--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.
•--debug-check
Print some debugging information when the program exits.
•--debug-info
Print debugging information and memory and CPU usage statistics when the program
exits.
•--dump-date
If the --comments option is given, mysqldump produces a comment at
the end of the dump of the following form:
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.
-- Dump completed on DATE
•--force, -f
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.
•--log-error=file_name
Log warnings and errors by appending them to the named file. The default is to
do no logging.
•--skip-comments
See the description for the --comments option.
•--verbose, -v
Verbose mode. Print more information about what the program does.
Help Options.PP The following options display information about the
mysqldump command itself.
•--help, -?
Display a help message and exit.
•--version, -V
Display version information and exit.
Internationalization Options.PP The following options change how the
mysqldump command represents character data with national language
settings.
•--character-sets-dir=dir_name
The directory where character sets are installed. See Section 10.5,
“Character Set Configuration”.
•--default-character-set=charset_name
Use charset_name as the default character set. See Section 10.5,
“Character Set Configuration”. If no character set is specified,
mysqldump uses utf8.
•--no-set-names, -N
Turns off the --set-charset setting, the same as specifying
--skip-set-charset.
•--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.PP 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.
•--apply-slave-statements
For a slave 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.
•--delete-master-logs
On a master replication server, delete the binary logs by sending a PURGE BINARY
LOGS statement to the server after performing the dump operation. This option
automatically enables --master-data.
•--dump-slave[=value]
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 replicating.
--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 handled.
This option causes mysqldump to stop the slave SQL thread before the dump
and restart it again after.
In conjunction with --dump-slave, the --apply-slave-statements and
--include-master-host-port options can also be used.
•--include-master-host-port
For the CHANGE MASTER TO statement in a slave 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 slave's master.
•--master-data[=value]
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 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.
This option 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 slave by dumping an existing slave of the
master, using the --dump-slave option, which overrides
--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”).
•--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.
The --set-gtid-purged option has the following effect on binary logging
when the dump file is reloaded:
Format Options.PP 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.
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. |
•--set-gtid-purged=OFF: SET
@@SESSION.SQL_LOG_BIN=0; is not added to the output.
•--set-gtid-purged=ON: SET
@@SESSION.SQL_LOG_BIN=0; is added to the output.
•--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).
This option was added in MySQL 5.6.9.•--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
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 5.1.7, “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. For example, --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.
•--complete-insert, -c
Use complete INSERT statements that include column names.
•--create-options
Include all MySQL-specific table options in the CREATE TABLE statements.
•--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 INFILE. See
Section 13.2.6, “LOAD DATA INFILE Syntax”.
•--hex-blob
Dump binary columns using hexadecimal notation (for example, 'abc' becomes
0x616263). The affected data types are BINARY, VARBINARY, the BLOB types, and
BIT.
•--lines-terminated-by=...
This option is used with the --tab option and has the same meaning as the
corresponding LINES clause for LOAD DATA INFILE. See Section 13.2.6,
“LOAD DATA INFILE Syntax”.
•--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.
•--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.
•--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 files *.txt file 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.
•--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
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.
The output from the mysql client when run using the --xml option
also follows the preceding rules. (See the section called “MYSQL
OPTIONS”.)
XML output from mysqldump includes the XML namespace, as shown here:
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)
Filtering Options.PP 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.
Value: | XML Representation: |
NULL (unknown value) | <field name="column_name" xsi:nil="true" /> |
'' (empty string) | <field name="column_name"></field> |
'NULL' (string value) | <field name="column_name">NULL</field> |
shell> 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>
•--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.
Prior to MySQL 5.6.4, the slave_master_info and slave_relay_log_info tables (see
Section 17.2.2, “Replication Relay and Status Logs”) were
not included by this option.
•--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.
•--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.
•--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.
•--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).
•--routines, -R
Include stored routines (procedures and functions) for the dumped databases in
the output. Use of 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.
Prior to MySQL 5.6.5, this option had no effect when used together with the
--xml option. (Bug #11760384, Bug #52792)
•--tables
Override the --databases or -B option. mysqldump regards
all name arguments following the option as table names.
•--triggers
Include triggers for each dumped table in the output. This option is enabled by
default; disable it with --skip-triggers.
•--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:
Performance Options.PP 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, or
mysqlhotcopy for MyISAM-only databases.
Performance is also affected by the transactional options, primarily for the
dump operation.
--where="user='jimf'" -w"userid>1" -w"userid<1"
•--delayed-insert
For those nontransactional tables that support the INSERT DELAYED syntax, use
that statement rather than regular INSERT statements.
As of MySQL 5.6.6, DELAYED inserts are deprecated, so this option will be
removed in a future release.
•--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.
•--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.
•--insert-ignore
Write INSERT IGNORE statements rather than INSERT statements.
•--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.
•--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.
•--skip-opt
See the description for the --opt option.
Transactional Options.PP The following options trade off the performance of the
dump operation, against the reliability and consistency of the exported data.
•--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 8.2.2.1, “Speed of INSERT Statements”.
•--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.
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.
•--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.
•--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.
•--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.
•--no-autocommit
Enclose the INSERT statements for each dumped table within SET autocommit = 0
and COMMIT statements.
•--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
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.
The server must be started with the --shared-memory option to enable
shared-memory connections.
•--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
•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.
•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.PP To make a backup of an entire database:
shell> mysqldump db_name > backup-file.sql
shell> mysql db_name < backup-file.sql
shell> mysql -e "source /path-to-backup/backup-file.sql" db_name
shell> mysqldump --opt db_name | mysql --host=remote_host -C db_name
shell> mysqldump --databases db_name1 [db_name2 ...] > my_databases.sql
shell> mysqldump --all-databases > all_databases.sql
shell> mysqldump --all-databases --master-data --single-transaction > all_databases.sql
shell> mysqldump --all-databases --master-data=2 > all_databases.sql
shell> mysqldump --all-databases --flush-logs --master-data=2 > all_databases.sql
•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
index disabling and table locking, use --skip-opt --disable-keys
--lock-tables.
Restrictions.
mysqldump does not dump the INFORMATION_SCHEMA or 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 the --skip-lock-tables option.
mysqldump does not dump the MySQL Cluster ndbinfo information database.
Before MySQL 5.6.6, mysqldump does not dump the general_log or
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 C.5, “Restrictions on Views” for a workaround.
COPYRIGHT¶
Copyright © 1997, 2016, Oracle and/or its affiliates. All rights reserved. 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/.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/).03/02/2016 | MySQL 5.6 |