mysqldump数据库备份参数详解(2)-木庄网络博客

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          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.

· --master-data[=value]

          This option causes the binary log position and filename to be
          written 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. value may be given as of
          MySQL 4.1.8; before that, do not specify an option value.

          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.

· --no-create-db, -n

          This option suppresses the CREATE DATABASE /*!32312 IF NOT EXISTS*/
          db_name 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 row information for the table. This is very useful
if you want to get a dump of only the structure for a table.

· --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. As of MySQL 4.1, --opt is on
          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.

· --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.

· --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. Added in MySQL 4.1.

· --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.

· --quote-names, -Q

          Quote database, table, and column names within ‘‘' characters. If
          the server SQL mode includes the ANSI_QUOTES option, names are
          quoted within ‘"' characters. As of MySQL 4.1.1, --quote-names is on
          by default. It can be disabled with --skip-quote-names, but this
          option should be given after any option such as --compatible that
          may enable --quote-names.

· --result-file=file, -r file

          Direct output to a given file. This option should be used on
          Windows, because it prevents newline ‘n' characters from being
          converted to ‘rn' carriage return/newline sequences.

· --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. This option was added in MySQL 4.1.2.

· --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 was added in MySQL 4.0.2. This
          option is mutually exclusive with the --lock-tables option, because
          LOCK TABLES causes any pending transactions to be committed
          implicitly.

To dump big tables, you should combine this option with --quick.

· --socket=path, -S path

The socket file to use when connecting to localhost (which is the
default host).

· --skip-comments

See the description for the --comments option.

· --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 .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--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.

· --tables

Override the --databases or -B option. All arguments following the
option are regarded as table names.

· --user=user_name, -u user_name

The MySQL username to use when connecting to the server.

· --verbose, -v

Verbose mode. Print out more information on what the program does.

· --version, -V

Display version information and exit.

· --where=��where-condition��, -w ��where-condition��

          Dump only records php/select">selected by the given WHERE condition. Note that
          quotes around the condition are mandatory if it contains spaces or
          characters that are special to your command interpreter.

Examples:

          "--where=user='jimf'"
          "-wuserid>1"
          "-wuserid<1"

· --xml, -X

Write dump output as well-formed XML.

You can also set the following variables by using --var_name=value
options:

· max_allowed_packet

          The maximum size of the buffer for client/server communication. The
          value of the variable can be up to 16MB before MySQL 4.0, and up to
          1GB from MySQL 4.0 on.

· 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. However,
       this syntax is deprecated as of MySQL 4.0.

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

If you want to dump all databases, use the --all-databases option:

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

       If tables are stored in the InnoDB storage engine, mysqldump provides a
       way of making an online backup of these (see command below). 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
       lock is released. So if and only if one long updating statement is
       running when the FLUSH... is issued, the MySQL server may get stalled
       until that long statement finishes, and then the dump becomes
       lock-free. So if the MySQL server receives only short (in the sense of
       "short execution time") updating statements, even if there are plenty
       of them, the initial lock period should not be noticeable.

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

       For point-in-time recovery (also known as “roll-forward”, when you need
       to restore an old backup and replay the changes which happened since
       that backup), it is often useful to rotate the binary log (see
       Section 8.4, “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 simultaneous use of --master-data and --single-transaction works as
       of MySQL 4.1.8. It 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 6.1, “Database
Backups”.

SEE ALSO
       isamchk(1), isamlog(1), msql2mysql(1), myisamchk(1), myisamlog(1),
       myisampack(1), mysql(1), mysql.server(1), mysql_config(1),
       mysql_fix_privilege_tables(1), mysql_zap(1), mysqlaccess(1),
       mysqladmin(1), mysqlbinlog(1), mysqlcheck(1), mysqld(1),
       mysqld_multi(1), mysqld_safe(1), mysqlhotcopy(1), mysqlimport(1),
       mysqlshow(1), pack_isam(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.

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