Mysqldump with available options

The mysqldump client is a backup program originally written by Igor Romanenko. It can be used to dump a database or a collection of databases for backup or transfer to another SQL server (not necessarily a MariaDB or MySQL server). The dump typically contains SQL statements to create the table, populate it, or both. However, mysqldumpcan also be used to generate files in CSV, other delimited text, or XML format.

If you are doing a backup on the server and your tables all are MyISAM tables, consider using mysqlhotcopy instead because it can accomplish faster backups and faster restores.

Usage

There are three general ways to invoke mysqldump:

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

If you do not name any tables following db_name or if you use the --databases or --all-databases option, entire databases are dumped.

mysqldump does not dump the INFORMATION_SCHEMA database by default. In all versions of MariaDB and in MySQL 5.1.38 and higher, mysqldump dumps INFORMATION_SCHEMA if you name it explicitly on the command line, although currently you must also use the --skip-lock-tablesoption. Before MySQL 5.1.38, mysqldump silently ignored INFORMATION_SCHEMA even if you named it explicitly on the command line.

To see a list of the options your version of mysqldump supports, execute mysqldump --help.

Option Groups

Some mysqldump options are shorthand for groups of other options:

  • Use of --opt is the same as specifying --add-drop-table--add-locks--create-options--disable-keys--extended-insert--lock-tables--quick, and --set-charset. All of the options that --opt stands for also are on by default because --opt is on by default.
  • Use of --compact is the same as specifying --skip-add-drop-table--skip-add-locks--skip-comments--skip-disable-keys, and --skip-set-charset options.

To reverse the effect of a group option, uses its --skip-xxx form (--skip-opt or --skip-compact). It is also possible to select only part of the effect of a group option by following it with options that enable or disable specific features. Here are some examples:

  • 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 --optis on by default.)
  • To reverse --opt for all features except index disabling and table locking, use --skip-opt --disable-keys --lock-tables.

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-optwould not have the intended effect; it is the same as --skip-opt by itself.

Row by Row vs. Buffering

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.

mysqldump in MariaDB 5.3 and higher

Starting in MariaDB 5.3mysqldump has been extended to support new enhancements for START TRANSACTION WITH CONSISTENT SNAPSHOT.

mysqldump and old versions of MySQL

If you are using a recent version of mysqldump to generate a dump to be reloaded into a very old MySQL server, you should not use the --opt or --extended-insert option. Use --skip-optinstead.

Note: mysqldump from MySQL 5.1.21 cannot be used to create dumps from MySQL server 5.1.20 and older. This issue is fixed in MySQL 5.1.22. (MySQL Bug #30123)

Options

mysqldump supports the following options, which can be specified on the command line or in the[mysqldump] and [client] option file groups. Default options are read from the following files in the given order:

  1. /etc/my.cnf
  2. /etc/mysql/my.cnf
  3. /usr/etc/my.cnf
  4. ~/.my.cnf

mysqldump also supports the options for processing option files.

The following options may be given as the first argument:

Option Description
--print-defaults Print the program argument list and exit.
--no-defaults Don’t read default options from any option file.
--defaults-file=# Only read default options from the given file #.
--defaults-extra-file=# Read this file after the global files are read.
--all Deprecated. Use --create-options instead.
-A, --all-databases Dump all the databases. This will be same as --databases with all databases selected.
-Y, --all-tablespaces Dump all the tablespaces.
-y, --no-tablespaces Do not dump any tablespace information.
--add-drop-database Add a DROP DATABASE before each create.
--add-drop-table Add a DROP TABLE before each create.
--add-locks Add locks around INSERT statements.
--allow-keywords Allow creation of column names that are keywords.
--character-sets-dir=name Directory for character set files.
-i, --comments Write additional information. Disable with --skip-comments.
--compatible=name Change the dump to be compatible with a given mode. By default tables are dumped in a format optimized for MySQL. Legal modes are: ansi,mysql323mysql40postgresqloraclemssqldb2maxdb,no_key_optionsno_table_options, and no_field_options. One can use several modes separated by commas.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.

Note: Requires MySQL server version 4.1.0 or higher. This option is ignored with earlier server versions.

--compact Give less verbose output (useful for debugging). Disables structure comments and header/footer constructs. Enables options --skip-add-drop-table--skip-add-locks--skip-comments--skip-disable-keys, and --skip-set-charset.
-c, --complete-insert Use complete INSERT statements that include column names.
-C, --compress Use compression in server/client protocol. Both client and server must support compression for this to work.
-a, --create-options Include all MariaDB and/or MySQL specific create options inCREATE TABLE statements.
-B, --databases Dump several databases. Normally, mysqldump treats the first name argument on the command line as a database name and following names as table names. With this option, it treats all name arguments as database names. CREATE DATABASE and USE statements are included in the output before each new database.
-#, --debug[=#] If using a debug version of MariaDB, 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´. If using a non-debug version, mysqldumpwill catch this and exit.
--debug-check Check memory and open file usage at exit.
--debug-info Print some debug info at exit.
--default-character-set=name Set the default character set to name. If no character set is specified,mysqldump uses utf8, and earlier versions use latin1.Prior to MySQL 5.1.38, this option has no effect for output data files produced by using the --tab option. See the description for that option for more details.
--delayed-insert Insert rows with INSERT DELAYED instead of INSERT.
--delete-master-logs On a master replication server, delete the binary logs by sending aPURGE BINARY LOGS statement to the server after performing the dump operation. This option automatically enables --master-data.
-K, --disable-keys '/*!40000 ALTER TABLE tb_name DISABLE KEYS */; and '/*!40000 ALTER TABLE tb_name ENABLE KEYS */; will be put in the output. This makes loading the dump file faster because the indexes are created after all rows are inserted. This option is effective only for non-unique indexes of MyISAM tables.
-E, --events Include Event Scheduler events for the dumped databases in the output. This option was added in MySQL 5.1.8.
-e, --extended-insert Use multiple-row INSERT syntax that include several VALUES lists. This results in a smaller dump file and speeds up inserts when the file is reloaded.
--fields-terminated-by=name Fields in the output file are terminated by the given string. Used with the --tab option and has the same meaning as the corresponding FIELDSclause for LOAD DATA INFILE.
--fields-enclosed-by=name Fields in the output file are enclosed by the given character. Used with the --tab option and has the same meaning as the corresponding FIELDSclause for LOAD DATA INFILE.
--fields-optionally-enclosed-by=name Fields in the output file are optionally enclosed by the given character. Used with the --tab option and has the same meaning as the corresponding FIELDS clause for LOAD DATA INFILE.
--fields-escaped-by=name Fields in the output file are escaped by the given character. Used with the --tab option and has the same meaning as the corresponding FIELDSclause for LOAD DATA INFILE.
--first-slave Deprecated, renamed to --lock-all-tables--first-slave is removed in MySQL 5.5.
-F, --flush-logs 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 --databases= or --all-databases option, the logs are flushed for each database dumped. The exception is when using --lock-all-tablesor --master-data: In this case, the logs are flushed only once, corresponding to the moment all tables are locked. If you want your dump and the log flush to happen at the same exact moment, you should use --flush-logs together with either --lock-all-tables or --master-data.
--flush-privileges Send a FLUSH PRIVILEGES statement to the server 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. This option was added in MySQL 5.1.12.
-f, --force 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 in this example,mysqldump exits with an error message. With --forcemysqldump prints the error message, but it also writes an SQL comment containing the view definition to the dump output and continues executing.
-?, --help Display a help message and exit.
--hex-blob Dump binary strings (BINARYVARBINARYBLOB) in hexadecimal format (for example, ´abc´ becomes 0x616263). The affected data types areBINARYVARBINARY, the BLOB types, and BIT.
-h, --host=name Connect to and dump data from the MariaDB or MySQL server on the given host. The default host is localhost.
--ignore-table=name Do not dump the specified table. To specify more than one table to ignore, use the directive multiple times, once for each table. Each table must be specified with both database and table names, e.g., --ignore-table=database.table. This option also can be used to ignore views.
--insert-ignore Insert rows with INSERT IGNORE instead of INSERT.
--lines-terminated-by=name Lines in the output file are terminated by the given string. This option is used with the --tab option and has the same meaning as the corresponding LINES clause for LOAD DATA INFILE.
-x, --lock-all-tables Lock all tables across all databases. This is achieved by acquiring a global read lock for the duration of the whole dump. This option automatically turns off --single-transaction and --lock-tables.
-l, --lock-tables For each dumped database, lock all tables to be dumped before dumping them. The tables are locked with READ LOCAL to allow concurrent inserts in the case of MyISAM tables. For transactional tables such as InnoDB, --single-transaction is a much better option than --lock-tablesbecause 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.
--log-error=name Log warnings and errors by appending them to the named file. The default is to do no logging. This option was added in MySQL 5.1.18.
--master-data[=#] This causes the binary log position and filename to be appended to the output. If equal to 1, will print it as a CHANGE MASTER command; if equal to 2, that command will be prefixed with a comment symbol. This option will turn --lock-all-tables on, unless --single-transaction is specified too (on servers before MariaDB 5.3 this will take a global read lock for a short time at the beginning of the dump; don’t forget to read about --single-transaction below). In all cases, any action on logs will happen at the exact moment of the dump. This option automatically turns --lock-tables off.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. To do this, use the following procedure on the existing slave:

1. Stop the slave´s SQL thread and get its current status:

mysql> STOP SLAVE SQL_THREAD;
mysql> SHOW SLAVE STATUS;

2. From the output of the SHOW SLAVE STATUS statement, the binary log coordinates of the master server from which the new slave should start replicating are the values of the Relay_Master_Log_File and Exec_Master_Log_Pos fields. Denote those values as file_name and file_pos.

2. Dump the slave server:

shell> mysqldump --master-data=2 --all-databases > dumpfile

3. Restart the slave:

mysql> START SLAVE;

4. On the new slave, load the dump file:

shell> mysql < dumpfile

5. On the new slave, set the replication coordinates to those of the master server obtained earlier:

mysql> CHANGE MASTER TO MASTER_LOG_FILE = ´file_name´, MASTER_LOG_POS = file_pos;

The CHANGE MASTER TO statement might also need other parameters, such as MASTER_HOST to point the slave to the correct master server host. Add any such parameters as necessary.

--max_allowed_packet=# The maximum packet length to send to or receive from server.
--net_buffer_length=# The buffer size for TCP/IP and socket communication.
--no-autocommit Enclose the INSERT statements for each dumped table withinSET autocommit = 0 and COMMIT statements.
-n, --no-create-db This option suppresses the CREATE DATABASE ... IF EXISTS statement that normally is output for each dumped database if --all-databases or--databases is given.
-t, --no-create-info Do not write CREATE TABLE statements which re-create each dumped table.
-d, --no-data Do not write any table row information (that is, do not dump table contents). This is useful if you want to dump only the CREATE TABLEstatement for the table (for example, to create an empty copy of the table by loading the dump file).
-N, --no-set-names Suppress the SET NAMES statement. This has the same effect as --skip-set-charset.
--opt This option is shorthand. It is the same as specifying --add-drop-table--add-locks--create-options--quick--extended-insert--lock-tables--set-charset, and --disable-keys. Enabled by default, disable with --skip-opt. It should give you a fast dump operation and produce a dump file that can be reloaded into a MySQL server quickly.The --opt option is enabled by default. Use --skip-opt to disable it. See the discussion at the beginning of this section for information about selectively enabling or disabling a subset of the options affected by --opt.
--order-by-primary Sorts each table’s rows by primary key, or first unique key, if such a key exists. This is useful when dumping a MyISAM table to be loaded into an InnoDB table, but will make the dump itself take considerably longer.
-p, --password[=name] 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 -poption on the command line, mysqldump prompts for one.Specifying a password on the command line should be considered insecure. You can use an option file to avoid giving the password on the command line.
-W, --pipe On Windows, connect to the server via a named pipe. This option applies only if the server supports named-pipe connections.
-P, --port=# The TCP/IP port number to use for the connection.
--protocol=name The connection protocol to use for connecting to the server (TCP, SOCKET, PIPE, MEMORY). It is useful when the other connection parameters normally would cause a protocol to be used other than the one you want.
-q, --quick 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 and to then dump the results directly to stdout rather than retrieving the entire row set and buffering it in memory before writing it out.
-Q, --quote-names Quote identifiers (such as database, table, and column names) within backtick (`) 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<<fixed.>--compatible<</code>> that may enable --quote-names.
--replace Use REPLACE INTO statements instead of INSERT INTO statements. This option was added in MySQL 5.1.3.
-r, --result-file=name Direct output to a given file. This option should be used on Windows to prevent newline "\n" characters from being converted to "\r\n"carriage return/newline sequences. The result file is created and its previous contents overwritten, even if an error occurs while generating the dump.
-R, --routines Included 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 using --routinescontains 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 mysql.proc table directly, using a MariaDB account which has appropriate privileges for the mysql database.

This option was added in MySQL 5.1.2. Before that, stored routines were not dumped. Routine DEFINER values were not dumped until MySQL 5.1.8. This means that before 5.1.8, when routines were reloaded, they would be created with the definer set to the reloading user. If you require routines to be re-created with their original definer, dump and load the contents of the mysql.proc table directly as described earlier.

--set-charset Add 'SET NAMES default_character_set' to the output. Enabled by default; suppress with --skip-set-charset.
-O, --set-variable=name Change the value of a variable. Please note that this option is deprecated; you can set variables directly with --variable-name=value.
--single-transaction This option 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 BEGIN 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. The dump is not guaranteed to be consistent for other storage engines. 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 TABLEDROP TABLERENAME TABLE, or 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 (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. So this option automatically turns off --lock-tables

This option is not supported for MySQL Cluster tables; the results cannot be guaranteed to be consistent due to the fact that the NDBCLUSTER storage engine supports only the READ_COMMITTED transaction isolation level. You should always use NDB backup and restore instead.

To dump large tables, you should combine the --single-transactionoption with --quick.

--dump-date If the --comments option and this option are 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. This option was added in MySQL 5.1.23.

--skip-opt Disable --opt. Disables --add-drop-table--add-locks--create-options--quick--extended-insert--lock-tables--set-charset, and --disable-keys.
-S, --socket=name For connections to localhost, the Unix socket file to use, or, on Windows, the name of the named pipe to use.
--ssl Enable SSL for connection (automatically enabled with other flags). Disable with --skip-ssl. All options which begin with --ssl (this one and the ones following) specify whether to connect to the server via SSL and indicate where to find SSL keys and certificates.
--ssl-ca=name CA file in PEM format (check OpenSSL docs, implies --ssl).
--ssl-capath=name CA directory (check OpenSSL docs, implies --ssl).
--ssl-cert=name X509 cert in PEM format (implies --ssl).
--ssl-cipher=name SSL cipher to use (implies --ssl).
--ssl-key=name X509 key in PEM format (implies --ssl).
--ssl-verify-server-cert Verify server’s “Common Name” in its cert against hostname used when connecting. This option is disabled by default.
-T, --tab=name Produce tab-separated text-format data files. With this option, for each dumped table mysqldump will create a tbl_name.sql file containing theCREATE TABLE statement that creates the table, and and a tbl_name.txtfile containing the table’s data. The option value is the directory in which to write the files.Note: This option can only be used 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 --fields-xxx and --lines-terminated-by options.

As of MySQL 5.1.38, column values are converted to the character set specified by the --default-character-set option. Prior to 5.1.38 or if no such option is present, values are dumped using the binary character set. In effect, there is no character set conversion. If a table contains columns in several character sets, the output data file will as well and you may not be able to reload the file correctly.

--tables This option overrides the --databases (-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.
--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. This option was added in MySQL 5.1.2.
-u, --user=name The MariaDB user name to use when connecting to the server.
-v, --verbose Verbose mode. Print more information about what the program is doing during various stages.
-V, --version Output version information and exit.
-w, --where=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"
-X, --xml Dump a database as well formed XML.

NULL, ´NULL´, and Empty Values in XML

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" />
´´ (empty string) <field name="column_name"></field>
´NULL´ (string value) <field name="column_name">NULL</field>

Beginning with MySQL 5.1.12, the output from the mysql client when run using the --xml option also follows the preceding rules.

Beginning with MySQL 5.1.18, XML output from mysqldump includes the XML namespace, as shown here:

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>

Variables

You can also set the following variables (--variable-name=value) and boolean options {FALSE|TRUE} by using:

Name Default Values Description
all TRUE
all-databases FALSE
all-tablespaces FALSE
no-tablespaces FALSE
add-drop-database FALSE
add-drop-table TRUE
add-locks TRUE
allow-keywords FALSE
character-sets-dir (No default value)
comments TRUE
compatible (No default value)
compact FALSE
complete-insert FALSE
compress FALSE
create-options TRUE
databases FALSE
debug-check FALSE
debug-info FALSE
default-character-set utf8
delayed-insert FALSE
delete-master-logs FALSE
disable-keys TRUE
events FALSE
extended-insert TRUE
fields-terminated-by (No default value)
fields-enclosed-by (No default value)
fields-optionally-enclosed-by (No default value)
fields-escaped-by (No default value)
first-slave FALSE
flush-logs FALSE
flush-privileges FALSE
force FALSE
hex-blob FALSE
host (No default value)
insert-ignore FALSE
lines-terminated-by (No default value)
lock-all-tables FALSE
lock-tables TRUE
log-error (No default value)
master-data 0
max_allowed_packet 25165824 The maximum size of the buffer for client/server communication. The maximum is 1GB.
net_buffer_length 1046528 The initial size of the buffer for client/server communication. When creating multiple-rowINSERT statements (as with the --extended-insert or --opt option), mysqldump creates rows up to net_buffer_length length. If you increase this variable, you should also ensure that the net_buffer_length variable in the MariaDB server is at least this large.
no-autocommit FALSE
no-create-db FALSE
no-create-info FALSE
no-data FALSE
order-by-primary FALSE
port 0
quick TRUE
quote-names TRUE
replace FALSE
routines FALSE
set-charset TRUE
single-transaction FALSE
dump-date TRUE
socket No default value)
ssl FALSE
ssl-ca (No default value)
ssl-capath (No default value)
ssl-cert (No default value)
ssl-cipher (No default value)
ssl-key (No default value)
ssl-verify-server-cert FALSE
tab (No default value)
triggers TRUE
tz-utc TRUE
user (No default value)
verbose FALSE
where (No default value)

Examples:

A common use of mysqldump is for making a backup of an entire database:

shell> mysqldump db_name > backup-file.sql

You can load the dump file back into the server like this:

shell> mysql db_name < backup-file.sql

Or like this:

shell> 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:

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

It is possible to dump several databases with one command:

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

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

shell> mysqldump --all-databases > all_databases.sql

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

shell> mysqldump --all-databases --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 5.2.4, “The Binary Log”) or at least know the binary log coordinates to which the dump corresponds:

shell> mysqldump --all-databases --master-data=2 > all_databases.sql

Or:

shell> 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.

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