MYSQLDUMP(1) MariaDB Database System MYSQLDUMP(1)NAMEmysqldump - a database backup program
SYNOPSISmysqldump [options] [db_name [tbl_name ...]]
DESCRIPTION
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
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/.
NOTES
1. Bug#30123
http://bugs.mysql.com/bug.php?id=30123
SEE ALSO
For more information, please refer to the MariaDB Knowledge Base,
available online at https://mariadb.com/kb/
AUTHOR
MariaDB Foundation (http://www.mariadb.org/).
MariaDB 10.1 14/12/2015 MYSQLDUMP(1)
