mysqldump(1)
NAME
mysqldump - a database backup program
SYNOPSIS
mysqldump [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 for
transferring the data to another SQL server (not
necessarily a MySQL server). The dump contains SQL
statements to create the table or populate it, or both.
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 [tables]
shell> mysqldump [options] --databases db_name1 [db_name2 db_name3...]
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.
To get a list of the options your version of mysqldump
supports, execute mysqldump --help.
If you run mysqldump without the --quick or --opt option,
mysqldump loads the whole result set into memory before
dumping the result. This can be a problem if you are
dumping a big database. The --opt option is enabled by
default, but can be disabled with --skip-opt.
If you are using a recent copy of the mysqldump program 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:
o --help, -?
Display a help message and exit.
o --add-drop-database
Add a DROP DATABASE statement before each CREATE
DATABASE statement.
o --add-drop-table
Add a DROP TABLE statement before each CREATE TABLE
statement.
o --add-locks
Surround each table dump with LOCK TABLES and UNLOCK
TABLES statements. This results in faster inserts when
the dump file is reloaded. See Section 2.16, "Speed of
INSERT Statements".
o --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.
o --allow-keywords
Allow creation of column names that are keywords. This
works by prefixing each column name with the table
name.
o --character-sets-dir=path
The directory where character sets are installed. See
Section 9.1, "The Character Set Used for Data and
Sorting".
o --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 additional,
use --skip-comments.
o --compact
Produce less verbose output. This option suppresses
comments and enables the --skip-add-drop-table,
--no-set-names, --skip-disable-keys, and
--skip-add-locks options.
o --compatible=name
Produce output that is more compatible with other
database systems or with older MySQL servers. The value
of name can be ansi, mysql323, mysql40, postgresql,
oracle, mssql, db2, maxdb, no_key_options,
no_table_options, or no_field_options. To use several
values, separate them by commas. These values have the
same meaning as the corresponding options for setting
the server SQL mode. See the section called "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.
o --complete-insert, -c
Use complete INSERT statements that include column
names.
o --compress, -C
Compress all information sent between the client and
the server if both support compression.
o --create-options
Include all MySQL-specific table options in the CREATE
TABLE statements.
o --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.
o --debug[=debug_options], -# [debug_options]
Write a debugging log. The debug_options string is
often 'd:t:o,file_name'. The default is
'd:t:o,/tmp/mysqldump.trace'.
o --default-character-set=charset_name
Use charset_name as the default character set. See
Section 9.1, "The Character Set Used for Data and
Sorting". If not specified, mysqldump uses utf8.
o --delayed-insert
Write INSERT DELAYED statements rather than INSERT
statements.
o --delete-master-logs
On a master replication server, delete the binary logs
after performing the dump operation. This option
automatically enables --master-data.
o --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 for MyISAM tables
only.
o --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.
o --fields-terminated-by=..., --fields-enclosed-by=...,
--fields-optionally-enclosed-by=...,
--fields-escaped-by=..., --lines-terminated-by=...
These options are used with the -T option and have the
same meaning as the corresponding clauses for LOAD DATA
INFILE. See Section 2.5, "LOAD DATA INFILE Syntax".
o --first-slave, -x
Deprecated. Now renamed to --lock-all-tables.
o --flush-logs, -F
Flush the MySQL server log files before starting the
dump. This option requires the RELOAD privilege. Note
that if you use this option in combination with the
--all-databases (or -A) 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.
o --force, -f
Continue even if an SQL error occurs during a table
dump.
o --host=host_name, -h host_name
Dump data from the MySQL server on the given host. The
default host is localhost.
o --hex-blob
Dump binary columns using hexadecimal notation (for
example, 'abc' becomes 0x616263). The affected data
types are BINARY, VARBINARY, and BLOB. As of MySQL
5.0.13, BIT columns are affected as well.
o --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.
o --insert-ignore
Write INSERT statements with the IGNORE option.
o --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.
o --lock-tables, -l
Lock all tables before starting the dump. The tables
are locked with READ LOCAL to allow concurrent inserts
in the case of MyISAM tables. For transactional tables
such as InnoDB and BDB, --single-transaction is a much
better option, because it does not need to lock the
tables at all.
Please note that when dumping multiple databases,
--lock-tables locks tables for each database
separately. So, 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.
o --master-data[=value]
Write the binary log filename and position to the
output. This option requires the RELOAD privilege and
the binary log must be enabled. If the option value is
equal to 1, the position and filename are written to
the dump output in the form of a CHANGE MASTER
statement that makes a slave server start from the
correct position in the master's binary logs if you use
this SQL dump of the master to set up a slave. If the
option value is equal to 2, the CHANGE MASTER statement
is written as an SQL comment. This is the default
action if value is omitted.
The --master-data option turns on --lock-all-tables,
unless --single-transaction also is specified (in which
case, a global read lock is only acquired a short time
at the beginning of the dump. See also the description
for --single-transaction. In all cases, any action on
logs happens at the exact moment of the dump. This
option automatically turns off --lock-tables.
o --no-autocommit
Enclose the INSERT statements for each dumped table
within SET AUTOCOMMIT=0 and COMMIT statements.
o --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.
o --no-create-info, -t
Do not write CREATE TABLE statements that re-create
each dumped table.
o --no-data, -d
Do not write any row information for the table. This is
very useful if you want to dump only the CREATE TABLE
statement for the table.
o --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
MySQL server quickly.
This option is enabled by default, but can be disabled
with --skip-opt. To disable only certain of the options
enabled by --opt, use their --skip forms; for example,
--skip-add-drop-table or --skip-quick.
o --order-by-primary
Sorts each table's rows by its primary key, or 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 itself take
considerably longer.
o --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, you are prompted for one.
Specifying a password on the command line should be
considered insecure. See Section 7.6, "Keeping Your
Password Secure".
o --port=port_num, -P port_num
The TCP/IP port number to use for the connection.
o --protocol={TCP|SOCKET|PIPE|MEMORY}
The connection protocol to use.
o --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.
o --quote-names, -Q
Quote database, table, and column names within ``'
characters. If the ANSI_QUOTES SQL mode is enabled,
names 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.
o --result-file=file, -r file
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.
o --routines, -R
Dump stored routines (functions and procedures) from
the dumped databases. 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 definer or the creation and modification
timestamps. This means that when the routines are
reloaded, they will be created with the definer set to
the reloading user and timestamps equal to the reload
time.
If you require routines to be re-created with their
original definer and timestamp attributes, do not use
--routines. Instead, dump and reload the contents of
the mysql.proc table directly, using a MySQL account
that has appropriate privileges for the mysql database.
This option was added in MySQL 5.0.13. Before that,
stored routines are not dumped.
o --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.
o --single-transaction
This option issues a BEGIN SQL statement before dumping
data from the server. It is useful only with
transactional tables such as InnoDB and BDB, 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 HEAP tables dumped while
using this option may still change state.
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 big tables, you should combine this option with
--quick.
o --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.
o --skip-comments
See the description for the --comments option.
o --tab=path, -T path
Produce tab-separated data files. For each dumped
table, mysqldump creates a tbl_name.sql file that
contains the CREATE TABLE statement that creates the
table, and a tbl_name.txt file that contains its data.
The option value is the directory in which to write the
files.
By default, the 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--xxx
options.
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.
o --tables
Override the --databases or -B option. All name
arguments following the option are regarded as table
names.
o --triggers
Dump triggers for each dumped table. This option is
enabled by default; disable it with --skip-triggers.
This option was added in MySQL 5.0.11. Before that,
triggers are not dumped.
o --tz-utc
Add SET TIME_ZONE='+00:00' to the dump file so that
TIMESTAMP columns can be dumped and reloaded between
servers in different time zones. 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. --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 5.0.15.
o --user=user_name, -u user_name
The MySQL username to use when connecting to the
server.
o --verbose, -v
Verbose mode. Print more information about what the
program does.
o --version, -V
Display version information and exit.
o --where='where_condition', -w 'where_condition'
Dump only rows selected by the given WHERE condition.
Note that 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"
o --xml, -X
Write dump output as well-formed XML.
You can also set the following variables by using
--var_name=value syntax:
o max_allowed_packet
The maximum size of the buffer for client/server
communication. The maximum is 1GB.
o net_buffer_length
The initial size of the buffer for client/server
communication. When creating multiple-row-insert
statements (as with option --extended-insert or --opt),
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 MySQL server
is at least this large.
It is also possible to set variables by using
--set-variable=var_name=value or -O var_name=value syntax.
This syntax is deprecated.
The most common use of mysqldump is probably for making a
backup of an entire database:
shell> mysqldump --opt db_name > backup-file.sql
You can read 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 just needs to acquire 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 and only if one long updating statement is
running when the FLUSH statement is issued, the MySQL
server may get stalled until that long statement finishes,
and then the dump becomes lock-free. 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 10.3, "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 simultaneous use of --master-data and
--single-transaction provides a convenient way to make an
online backup suitable for point-in-time recovery if
tables are stored in the InnoDB storage engine.
For more information on making backups, see Section 8.1,
"Database Backups", and Section 8.2, "Example Backup and
Recovery Strategy".
SEE ALSO
msql2mysql(1), myisamchk(1), myisamlog(1), myisampack(1),
mysql(1), mysql.server(1), mysql_config(1),
mysql_fix_privilege_tables(1), mysql_upgrade(1),
mysql_zap(1), mysqlaccess(1), mysqladmin(1),
mysqlbinlog(1), mysqlcheck(1), mysqld(1), mysqld_multi(1),
mysqld_safe(1), mysqlhotcopy(1), mysqlimport(1),
mysqlmanager(1), mysqlshow(1), perror(1), replace(1),
safe_mysqld(1)
For more information, please refer to the MySQL Reference
Manual, which may already be installed locally and which
is also available online at http://dev.mysql.com/doc/.
AUTHOR
MySQL AB (http://www.mysql.com/). This software comes
with no warranty.
MySQL 5.0 03/04/2006 FBMYSQLDUMPFR(1)
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