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NAME | SYNOPSIS | DESCRIPTION | COPYRIGHT | NOTES | SEE ALSO | AUTHOR | COLOPHON |
MYSQLDUMP(1) MariaDB Database System MYSQLDUMP(1)
mysqldump - a database backup program
mysqldump [options] [db_name [tbl_name ...]]
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 server). The dump typically contains SQL
statements to create the table, populate it, or both. However,
mysqldump can 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 the mysqlhotcopy instead because it can
accomplish faster backups and faster restores. See mysqlhotcopy(1).
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 or performance_schema
databases by default. To dump these, name them explicitly on the
command line, although you must also use the --skip-lock-tables
option.
To see a list of the options your version of mysqldump supports,
execute mysqldump --help.
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 --opt is 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-opt would not have the
intended effect; it is the same as --skip-opt by itself.
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, you should not use the
--opt or --extended-insert option. Use --skip-opt instead.
mysqldump supports the following options, which can be specified on
the command line or in the [mysqldump] and [client] option file
groups. mysqldump also supports the options for processing option
file.
· --help, -?
Display a help message and exit.
· --add-drop-database
Add 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
Add a DROP TABLE statement before each CREATE TABLE statement.
· --add-locks
Surround each table dump with LOCK TABLES and UNLOCK TABLES
statements. This results in faster inserts when the dump file is
reloaded.
· --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.
· --all-tablespaces, -Y
Adds to a table dump all SQL statements needed to create any
tablespaces used by an NDBCLUSTER table. This information is not
otherwise included in the output from mysqldump. This option is
currently relevant only to MySQL Cluster tables.
· --allow-keywords
Allow creation of column names that are keywords. This works by
prefixing each column name with the table name.
· --apply-slave-statements
Adds 'STOP SLAVE' prior to 'CHANGE MASTER' and 'START SLAVE' to
bottom of dump.
· --character-sets-dir=path
The directory where character sets are installed.
· --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.
· --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.
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.
· --complete-insert, -c
Use complete INSERT statements that include column names.
· --compress, -C
Compress all information sent between the client and the server
if both support compression.
· --create-options, -a
Include all MariaDB-specific table options in the CREATE TABLE
statements. Use --skip-create-options to disable.
· --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.
· --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.
· --default-auth
Default authentication client-side plugin to use.
· --default-character-set=charset_name
Use charset_name as the default character set. If no character
set is specified, mysqldump uses utf8.
· --defaults-extra-file=filename
Set filename as the file to read default options from after the
global defaults files has been read. Must be given as first
option.
· --defaults-file=filename
Set filename as the file to read default options from, override
global defaults files. Must be given as first option.
· --defaults-group-suffix=str,
Also read groups with a suffix of str. For example, since
mysqldump normally reads the [client] and [mysqldump] groups,
--defaults-group-suffix=x would cause it to also read the groups
[mysqldump_x] and [client_x].
· --delayed-insert
Write INSERT DELAYED statements rather than INSERT statements.
· --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.
· --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.
· --dump-date
If the --comments option is given, mysqldump produces a comment
at the end of the dump of the following form:
-- Dump completed on DATE
However, the date causes dump files taken at different times to
appear to be different, even if the data are otherwise identical.
--dump-date and --skip-dump-date control whether the date is
added to the comment. The default is --dump-date (include the
date in the comment). --skip-dump-date suppresses date printing
· --dump-slave[=value]
Used for producing a dump file from a replication slave server
that can be used to set up another slave server with the same
master. Causes the binary log position and filename of the master
to be appended to the dumped data output. Setting the value to 1
(the default) will print it as a CHANGE MASTER command in the
dumped data output; if set 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 (in which case a
global read lock is only taken 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. Option automatically turns --lock-tables off.
Using this option causes mysqldump to stop the slave SQL thread
before beginning the dump, and restart it again after completion.
· --events, -E
Include Event Scheduler events for the dumped databases in the
output.
· --extended-insert, -e
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=..., --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.
· --first-slave
Removed in MariaDB 5.5. Use --lock-all-tables instead.
· --flush-logs, -F
Flush the MariaDB 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 or --master-data: 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 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.
· --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.
· --gtid
Available from MariaDB 10.0.13, and is used together with
--master-data and --dump-slave to more conveniently set up a new
GTID slave. It causes those options to output SQL statements that
configure the slave to use the global transaction ID to connect
to the master instead of old-style filename/offset positions. The
old-style positions are still included in comments when --gtid is
used; likewise the GTID position is included in comments even if
--gtid is not used.
· --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.
· --host=host_name, -h host_name
Dump data from the MariaDB server on the given host. The default
host is localhost.
· --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.
· --include-master-host-port
Add the MASTER_HOST and MASTER_PORT options for the CHANGE MASTER
TO statement when using the --dump-slave option for a slave dump.
· --insert-ignore
Write INSERT IGNORE statements rather than INSERT statements.
· --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.
· --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 allow
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.
Use --skip-lock-tables to disable.
· --log-error=file_name
Log warnings and errors by appending them to the named file. The
default is to do no logging.
· --log-queries
When restoring the dump, the server will, if logging is turned
on, log the queries to the general and slow query log. Defaults
to on; use --skip-log-queries to disable.
· --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 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.
3. Dump the slave server:
shell> mysqldump --master-data=2 --all-databases > dumpfile
4. Restart the slave:
mysql> START SLAVE;
5. On the new slave, load the dump file:
shell> mysql < dumpfile
6. 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=length
Sets the maximum packet length to send to or receive from server.
· --net-buffer-length=length
Sets the 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, -n
This option suppresses 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 re-create each dumped
table.
· --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).
· --no-defaults
Do not read default options from any option file. This must be
given as the first argument.
· --no-set-names, -N
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 --disable-keys
--extended-insert --lock-tables --quick --set-charset. It should
give you a fast dump operation and produce a dump file that can
be reloaded into a MariaDB 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
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
will make the dump operation take considerably longer.
· --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. You can use an option file to avoid giving the password
on the command line.
· --pipe, -W
On Windows, connect to the server via a named pipe. This option
applies only if the server supports named-pipe connections.
· --plugin-dir
Directory for client-side plugins.
· --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.
· --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.
· --print-defaults
Print the program argument list and exit. This must be given as
the first argument.
· --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.
· --replace
Write REPLACE statements rather than INSERT statements.
· --result-file=file_name, -r 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.
· --routines, -R
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
by using --routines contains 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 that has appropriate privileges for the mysql
database.
· --set-charset
Add SET NAMES default_character_set to the output. This option is
enabled by default. To suppress the SET NAMES statement, use
--skip-set-charset.
· --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. 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, you should combine the --single-transaction
option with --quick.
· --skip-add-drop-table
Disable the --add-drop-table option.
· --skip-add-locks
Disable the --add-locks option.
· --skip-comments
Disable the --comments option.
· --skip-compact
Disable the --compact option.
· --skip-disable-keys
Disable the --disable-keys option.
· --skip-extended-insert
Disable the --extended-insert option.
· --skip-opt
Disable the --opt option.
· --skip-quick
Disable the --quick option.
· --skip-quote-names
Disable the --quote-names option.
· --skip-set-charset
Disable the --set-charset option.
· --skip-triggers
Disable the --triggers option.
· --skip-tz-utc
Disable the --tz-utc option.
· --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
Enable SSL for connection (automatically enabled with other
flags). Disable with --skip-ssl.
· --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 (check OpenSSL docs, implies --ssl).
· --ssl-cipher=name
SSL cipher to use (check OpenSSL docs, implies --ssl).
· --ssl-key=name
X509 key in PEM format (check OpenSSL docs, implies --ssl).
· --ssl-crl=name
Certificate revocation list (check OpenSSL docs, implies --ssl).
· --ssl-crlpath=name
Certificate revocation list path (check OpenSSL docs, 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.
· --tab=path, -T path
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. 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.
Column values are converted to the character set specified by the
--default-character-set option.
· --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.
· --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.
· --user=user_name, -u user_name
The MariaDB user name to use when connecting to the server.
· --verbose, -v
Verbose mode. Print more information about what the program does.
· --version, -V
Display version information and exit.
· --where=´where_condition´, -w ´where_condition´
Dump only rows selected by the given WHERE condition. Quotes
around the condition are mandatory if it contains spaces or other
characters that are special to your command interpreter.
Examples:
--where="user=´jimf´"
-w"userid>1"
-w"userid<1"
· --xml, -X
Write dump output as well-formed XML.
NULL, ´NULL´, and Empty Values: For a column named column_name,
the NULL value, an empty string, and the string value ´NULL´ are
distinguished from one another in the output generated by this
option as follows.
┌──────────────────────┬─────────────────────────────────────────┐
│Value: │ XML Representation: │
├──────────────────────┼─────────────────────────────────────────┤
│NULL (unknown value) │ <field name="column_name" │
│ │ xsi:nil="true" /> │
├──────────────────────┼─────────────────────────────────────────┤
│´´ (empty string) │ <field name="column_name"></field> │
├──────────────────────┼─────────────────────────────────────────┤
│´NULL´ (string value) │ <field name="column_name">NULL</field> │
└──────────────────────┴─────────────────────────────────────────┘
The output from the mysql client when run using the --xml option
also follows the preceding rules. (See the section called “MYSQL
OPTIONS”.)
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>
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 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 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.
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 MariaDB 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 MariaDB 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 MariaDB 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 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.
If you encounter problems backing up views, please read the section
that covers restrictions on views which describes a workaround for
backing up views when this fails due to insufficient privileges.
Copyright 2007-2008 MySQL AB, 2008-2010 Sun Microsystems, Inc.,
2010-2015 MariaDB Foundation
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/.
1. Bug#30123
http://bugs.mysql.com/bug.php?id=30123
For more information, please refer to the MariaDB Knowledge Base,
available online at https://mariadb.com/kb/
MariaDB Foundation (http://www.mariadb.org/).
This page is part of the MariaDB (MariaDB database server) project.
Information about the project can be found at ⟨http://mariadb.org/⟩.
If you have a bug report for this manual page, see
⟨https://mariadb.com/kb/en/mariadb/reporting-bugs/⟩. This page was
obtained from the project's upstream Git repository
⟨https://github.com/MariaDB/server⟩ on 2017-07-05. If you discover
any rendering problems in this HTML version of the page, or you
believe there is a better or more up-to-date source for the page, or
you have corrections or improvements to the information in this
COLOPHON (which is not part of the original manual page), send a mail
to man-pages@man7.org
MariaDB 10.1 14/12/2015 MYSQLDUMP(1)
Pages that refer to this page: mysql(1)