Your 1st mysqldump makes table structures and INSERTs and puts it in dump.sql.
Your 2nd dump is a remote dump that is piped straight into mysql in localhost.
If you are trying to catch any output based on errors, try this:
mysqldump -alv -h 123.123.123.123 --user=username --password=p@ssw0rd --add-drop-table databasename 2> output.log | mysql --user=username --password=p@ssw0rd -h localhost localdatabase
Using 2>
will catch any error-based output (aka stderr). The mysqldump should still pipe normal console output (aka stdout) to the other mysql session and load the data as intended.
EXAMPLE : I have a small database called sample on my PC.
I ran this:
C:LWDBA>mysqldump -u... -p... --verbose sample 2>sample.txt > sample.sql
C:LWDBA>type sample.txt
-- Connecting to localhost...
-- Retrieving table structure for table users...
-- Sending SELECT query...
-- Retrieving rows...
-- Disconnecting from localhost...
C:LWDBA>type sample.sql
-- MySQL dump 10.13 Distrib 5.5.12, for Win64 (x86)
--
-- Host: localhost Database: sample
-- ------------------------------------------------------
-- Server version 5.5.12-log
/*!40101 SET @OLD_CHARACTER_SET_CLIENT=@@CHARACTER_SET_CLIENT */;
/*!40101 SET @OLD_CHARACTER_SET_RESULTS=@@CHARACTER_SET_RESULTS */;
/*!40101 SET @OLD_COLLATION_CONNECTION=@@COLLATION_CONNECTION */;
/*!40101 SET NAMES utf8 */;
/*!40103 SET @OLD_TIME_ZONE=@@TIME_ZONE */;
/*!40103 SET TIME_ZONE='+00:00' */;
/*!40014 SET @OLD_UNIQUE_CHECKS=@@UNIQUE_CHECKS, UNIQUE_CHECKS=0 */;
/*!40014 SET @OLD_FOREIGN_KEY_CHECKS=@@FOREIGN_KEY_CHECKS, FOREIGN_KEY_CHECKS=0 */;
/*!40101 SET @OLD_SQL_MODE=@@SQL_MODE, SQL_MODE='NO_AUTO_VALUE_ON_ZERO' */;
/*!40111 SET @OLD_SQL_NOTES=@@SQL_NOTES, SQL_NOTES=0 */;
--
-- Table structure for table `users`
--
DROP TABLE IF EXISTS `users`;
/*!40101 SET @saved_cs_client = @@character_set_client */;
/*!40101 SET character_set_client = utf8 */;
CREATE TABLE `users` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`users_tbl_points` int(11) NOT NULL,
`users_tbl_rank` int(11) NOT NULL DEFAULT '0',
PRIMARY KEY (`id`),
KEY `users_tbl_points` (`users_tbl_points`)
) ENGINE=InnoDB AUTO_INCREMENT=31 DEFAULT CHARSET=latin1;
/*!40101 SET character_set_client = @saved_cs_client */;
--
-- Dumping data for table `users`
--
LOCK TABLES `users` WRITE;
/*!40000 ALTER TABLE `users` DISABLE KEYS */;
INSERT INTO `users` VALUES (1,785523,9),(2,443080,20),(3,858830,7),(4,964909,3),(5,248056,24),
(6,345553,21),(7,983596,2),(8,881325,6),(9,455836,19),(10,635204,16),(11,808514,8),
(12,136960,28),(13,259255,22),(14,885399,5),(15,649229,15),(16,589948,18),(17,2055,30),
(18,240429,25),(19,195981,26),(20,258620,23),(21,705158,12),(22,749931,11),(23,634182,17),
(24,921117,4),(25,703038,13),(26,751842,10),(27,650093,14),(28,994943,1),(29,24437,29),
(30,137355,27);
/*!40000 ALTER TABLE `users` ENABLE KEYS */;
UNLOCK TABLES;
/*!40103 SET TIME_ZONE=@OLD_TIME_ZONE */;
/*!40101 SET SQL_MODE=@OLD_SQL_MODE */;
/*!40014 SET FOREIGN_KEY_CHECKS=@OLD_FOREIGN_KEY_CHECKS */;
/*!40014 SET UNIQUE_CHECKS=@OLD_UNIQUE_CHECKS */;
/*!40101 SET CHARACTER_SET_CLIENT=@OLD_CHARACTER_SET_CLIENT */;
/*!40101 SET CHARACTER_SET_RESULTS=@OLD_CHARACTER_SET_RESULTS */;
/*!40101 SET COLLATION_CONNECTION=@OLD_COLLATION_CONNECTION */;
/*!40111 SET SQL_NOTES=@OLD_SQL_NOTES */;
-- Dump completed on 2012-03-02 15:49:54
C:LWDBA>
Give it a Try !!!
В этом топике я хочу рассказать вам о том, как проверить бэкапы MySQL баз данных, снятых с помощью утилиты mysqldump.
В один прекрасный день, я не смог поднять базу с бэкапа, благо, что это было не критично и в итоге, встала задача, что их нужно как-то проверять на целостность.
Бэкапы снимал с помощью AutoMySQLBackup скрипта.
Как снимаются бэкапы
Скрипт я чуточку дописал. Патч на automysqlbackup.sh:
--- prod/automysqlbackup 2011-11-15 11:20:12.193119699 +0600
+++ dev/automysqlbackup 2011-11-18 15:43:49.797113371 +0600
@@ -89,6 +89,14 @@
# For connections to localhost. Sometimes the Unix socket file must be specified.
SOCKET=
+# Logs
+MDERR=/var/log/mysqldump.error
+MDLOG=/var/log/mysqldump.log
+MDALL=/var/log/mysqldumperr.log
+MD5LOG=/var/log/md5.log
+LATF=/var/log/latest-backup
+TMPFILE=$(mktemp /tmp/XXXXXX)
+CDATE=$(date +%F)
# Command to run before backups (uncomment to use)
#PREBACKUP="/etc/mysql-backup-pre"
@@ -406,7 +414,16 @@
# Database dump function
dbdump () {
-mysqldump --user=$USERNAME --password=$PASSWORD --host=$DBHOST $OPT $1 > $2
+mysqldump --user=$USERNAME --password=$PASSWORD --host=$DBHOST $OPT $1 > $2 2>$TMPFILE
+sed -i "s|^|[$CDATE] |" $TMPFILE
+cat $TMPFILE >> $MDALL
+cat /dev/null > $TMPFILE
+ret="$?"
+if [ "$ret" -ne "0" ]; then
+ echo "$1 NOT backuped at `date +%F` with exit status $ret">> $MDERR
+else
+ echo "$1 backuped SUCESSFULLY at `date +%F` with exit status $ret" >> $MDLOG
+fi
return 0
}
@@ -468,7 +485,7 @@
# If backing up all DBs on the server
if [ "$DBNAMES" = "all" ]; then
- DBNAMES="`mysql --user=$USERNAME --password=$PASSWORD --host=$DBHOST --batch --skip-column-names -e "show databases"| sed 's/ /%/g'`"
+ DBNAMES="`mysql --user=$USERNAME --password=$PASSWORD --host=$DBHOST --batch --skip-column-names -e "show databases"| sed 's/ /%/g'|grep -v -E '_schema|^mysql'`"
# If DBs are excluded
for exclude in $DBEXCLUDE
@@ -506,6 +523,8 @@
dbdump "$MDB" "$BACKUPDIR/monthly/$MDB/${MDB}_$DATE.$M.$MDB.sql"
compression "$BACKUPDIR/monthly/$MDB/${MDB}_$DATE.$M.$MDB.sql"
BACKUPFILES="$BACKUPFILES $BACKUPDIR/monthly/$MDB/${MDB}_$DATE.$M.$MDB.sql$SUFFIX"
+ echo `md5sum -b $BACKUPFILES` >> $MD5LOG
+ echo $BACKUPFILES >> $LATF
echo ----------------------------------------------------------------------
done
fi
@@ -542,6 +561,8 @@
dbdump "$DB" "$BACKUPDIR/weekly/$DB/${DB}_week.$W.$DATE.sql"
compression "$BACKUPDIR/weekly/$DB/${DB}_week.$W.$DATE.sql"
BACKUPFILES="$BACKUPFILES $BACKUPDIR/weekly/$DB/${DB}_week.$W.$DATE.sql$SUFFIX"
+ echo `md5sum -b $BACKUPFILES` >> $MD5LOG
+ echo $BACKUPFILES >> $LATF
echo ----------------------------------------------------------------------
# Daily Backup
@@ -553,6 +574,8 @@
dbdump "$DB" "$BACKUPDIR/daily/$DB/${DB}_$DATE.$DOW.sql"
compression "$BACKUPDIR/daily/$DB/${DB}_$DATE.$DOW.sql"
BACKUPFILES="$BACKUPFILES $BACKUPDIR/daily/$DB/${DB}_$DATE.$DOW.sql$SUFFIX"
+ echo `md5sum -b $BACKUPFILES` >> $MD5LOG
+ echo $BACKUPFILES >> $LATF
echo ----------------------------------------------------------------------
fi
done
@@ -569,6 +592,8 @@
dbdump "$MDBNAMES" "$BACKUPDIR/monthly/$DATE.$M.all-databases.sql"
compression "$BACKUPDIR/monthly/$DATE.$M.all-databases.sql"
BACKUPFILES="$BACKUPFILES $BACKUPDIR/monthly/$DATE.$M.all-databases.sql$SUFFIX"
+ echo `md5sum -b $BACKUPFILES` >> $MD5LOG
+ echo $BACKUPFILES >> $LATF
echo ----------------------------------------------------------------------
fi
@@ -589,6 +614,8 @@
dbdump "$DBNAMES" "$BACKUPDIR/weekly/week.$W.$DATE.sql"
compression "$BACKUPDIR/weekly/week.$W.$DATE.sql"
BACKUPFILES="$BACKUPFILES $BACKUPDIR/weekly/week.$W.$DATE.sql$SUFFIX"
+ echo `md5sum -b $BACKUPFILES` >> $MD5LOG
+ echo $BACKUPFILES >> $LATF
echo ----------------------------------------------------------------------
# Daily Backup
@@ -601,6 +628,8 @@
dbdump "$DBNAMES" "$BACKUPDIR/daily/$DATE.$DOW.sql"
compression "$BACKUPDIR/daily/$DATE.$DOW.sql"
BACKUPFILES="$BACKUPFILES $BACKUPDIR/daily/$DATE.$DOW.sql$SUFFIX"
+ echo `md5sum -b $BACKUPFILES` >> $MD5LOG
+ echo $BACKUPFILES >> $LATF
echo ----------------------------------------------------------------------
fi
echo Backup End Time `date`
@@ -685,6 +714,5 @@
# Clean up Logfile
eval rm -f "$LOGFILE"
eval rm -f "$LOGERR"
-
+eval rm -f "$TMPFILE"
exit $STATUS
-
Проверка целостности бэкапа
Всё. Теперь мы знаем имя файла с последним бэкапом, пишем лог ошибок mysqldump в формате «date +%F $ERROR» и снимаем md5-hash от файла бэкапа.
Так как бэкапы получаются сжатые gzip’ом, и вне сжатого бэкапа находится примерно такая строка:
-- MySQL dump 10.13 Distrib 5.5.16, for Linux (i686)
А в конце примерно такая:
-- Dump completed on 2011-11-15 17:22:16
то мы можем использовать zcat и проверять целостность примерно таким скриптом:
#!/bin/bash
CDATE=`date +%F`
LF=`cat /var/log/latest-backup| grep $CDATE`
LOG=/var/log/checker.log
BEGIN=`zcat $LF | grep ^'-- M' | wc -l`
END=`zcat $LF | grep ^'-- Dump c' | wc -l`
if [ "$BEGIN" == "1" ];then
if [ "$END" == "1" ];then
echo `date +%F-%H-%M` $LF is OK >> $LOG
else
echo `date +%F-%H-%M` $LF is corrupted >> $LOG
fi
else
echo `date +%F-%H-%M` $LF is corrupted >> $LOG
fi
Добавляем скрипты в крон, проверяем логи.
7 июня 2009 г.
MyISAM
MySQL
InnoDB
Бэкап
Утилита mysqldump позволяет получить дамп содержимого базы данных или совокупности баз для создания резервной копии или пересылки данных на другой SQL-сервер (не обязательно MySQL-сервер). Дамп будет содержать набор команд SQL для создания и/или заполнения таблиц.
Так же mysqldump имеет возможность развертывания баз данных из созданного sql-файла.
Создание дампа
Разберем пример простейшее использования, задампим базу данных «database» при помощи перенаправления потока в файл «database.sql»:
mysqldump -uroot -h82.82.82.82 -p database > database.sql
где:
- -u или -–user=… — имя пользователя
- -h или —host=… — удаленный хост (для локального хоста можно опустить этот параметр)
- -p или —password — запросить пароль
- database — имя базы данных
- database.sql — файл для дампа
Для того чтобы сделать дамп несколько баз данных, необходимо использовать параметр —databases (или сокращенно -B), пример:
mysqldump -uroot -h82.82.82.82 -p -B database1 database2 database3 > databases.sql
А для того чтобы сделать дамп всех баз данных, необходимо использовать параметр —all-databases (или сокращенно -A), пример:
mysqldump -uroot -h82.82.82.82 -p -A > all-databases.sql
Развертывание дампа
Перенаправляем поток в обратную сторону и развертываем базу данных:
mysql -uroot -h82.82.82.82 -p database < database.sql
Или через mysql-console:
mysql> use database; mysql> source database.sql
Ну, а если у нас gz-архив к примеру, то:
zcat database.sql.gz | mysql -uroot -h82.82.82.82 -p database
Пример использование некоторых параметров
Например, нам нужны данные с «продакшен версии базы» для «версии разработчика», то есть нам нужна «песочница». Выбираем не более 100 записей:
mysqldump -uroot -h82.82.82.82 -p --where="true limit 100" database > database.sql
Или нам нужна только структура, без данных:
mysqldump -uroot -h82.82.82.82 -p --no-data database > database.sql
Примеры навеяны постом Александра Макарова — http://rmcreative.ru/blog/post/ljogkiy-damp-mysql
Делаем дамп только триггеров, процедур и событий:
mysqldump --no-create-info --no-data --triggers --routines --events -uroot -p database | gzip > ~/database.sql.gz
Шпаргалка по параметрам
Приведу некоторые параметры, которые могут понадобится при работе с утилитой mysqldump.
- —add-drop-database
- Добавляет оператор DROP DATABASE перед каждым оператором CREATE DATABASE.
- —add-drop-table
- Добавляет оператор DROP TABLE перед каждым оператором CREATE TABLE.
- —add-locks
- Добавляет оператор LOCK TABLES перед выполнением и UNLOCK TABLE после выполнения каждого дампа таблицы (для ускорения доступа к MySQL).
- —all-databases, -A
- Сохраняет все таблицы из всех баз данных, которые находятся под управлением текущего сервера.
- —allow-keywords
- Разрешить создавать имена столбцов, которые совпадают с ключевыми словами. Отсутствие конфликтов обеспечивается прибавлением имени таблицы в качестве префикса к имени каждого столбца.
- —comments, -i
- Данный параметр позволяет добавить в дамп дополнительную информацию, такую, как версия mysqldump, версия MySQL, имя хоста, на котором расположен сервер MySQL.
- —compact
- Данный параметр требует от mysqldump создать дамп, используя как можно более компактный формат. Параметр является противоположным —comments.
- —compatible=name
- Параметр генерирует вывод, который совместим с другими СУБД или более старыми версиями MySQL. Вместо ключевого слова name можно использовать: «ansi», «mysql323», «mysql40», «postgresql», «oracle», «mssql», «db2», «maxdb», «no_key_options», «no_table_options», «no_field_options». Можно использовать несколько значений, разделив их запятыми.
- —complete-insert, -c
- Используется полная форма оператора INSERT (с именами столбцов).
- —create-options
- Добавляет дополнительную информацию в операторы CREATE TABLE. Это может быть тип таблицы, начальное значение AUTO_INCREMENT и другие параметры.
- —databases, -B
- Параметр позволяет указать имена нескольких баз данных, для которых необходимо создать дамп.
- —delayed
- Использовать команду INSERT DELAYED при вставке строк.
- —delete-master-logs
- На главном сервере репликации автоматически удаляются бинарные логи (logbin) после того, как дамп был успешно создан при помощи mysqldump. Этот параметр автоматически включает параметр «—master-data».
- —disable-keys, -K
- Для каждой таблицы, окружает оператор INSERT выражениями /*!40000 ALTER TABLE tbl_name DISABLE KEYS */; и /*!40000 ALTER TABLE tbl_name ENABLE KEYS */; в выводе результата дампа. Это ускорит загрузку данных на сервер для таблиц типа MyISAM, так как индексы создаются после внесения всех данных.
- —extended-insert, -e
- Использовать команду INSERT с новым многострочным синтаксисом (повышает компактность и быстродействие операторов ввода).
- —flush-logs, -F
- Записать на диск данные системного журнала из буфера MySQL-сервера перед началом выполнения дампа.
- —force, -f
- Продолжать даже если в процессе создания дампа произошла ошибка.
- —hex-blob
- Параметр позволяет представить бинарные данные в полях типа BINARY, VARBINARY, BLOB и BIT в шестнадцатеричном формате. Так последовательность «abc» будет заменена на 0x616263.
- —ignore-table=db_name.tbl_name
- Позволяет игнорировать таблицу tbl_name базы данных db_name при создании дампа. Если из дампа необходимо исключить несколько таблиц, необходимо использовать несколько параметров «—ignore-table», указывая по одной таблице в каждом из параметров.
- —insert-ignore
- Добавляет ключевое слово IGNORE в оператор INSERT.
- —lock-all-tables, -x
- Указание этого параметра приводит к блокировке всех таблиц во всех базах данных на время создания полного дампа всех баз данных.
- —lock-tables, -l
- Указание этого параметра приводит к блокировке таблиц базы данных, для которой создается дамп.
- —no-autocommit
- Включает все операторы INSERT, относящиеся к одной таблице, в одну транзакцию, что приводит к увеличению скорости загрузки данных.
- —no-create-db, -n
- Подавляет создание в дампе операторов CREATE DATABASE, которые автоматически добавляются при использовании параметров —databases и —all-databases.
- —no-data, -d
- Подавляет создание операторов INSERT в дампе, что может быть полезно при создании дампа структуры базы данных без самих данных.
- —opt
- Параметр предназначен для оптимизации скорости резервирования данных и является сокращением, включающим следующие опции: —quick —add-drop-table —add-locks —create-options —disable-keys —extended-insert —lock-tables —set-charset. Начиная с MySQL 4.1, параметр —opt используется по умолчанию, т.е. все вышеперечисленные параметры включаются по умолчанию, даже если они не указываются. Для того чтобы исключить такое поведение, необходимо воспользоваться параметров —skip-opt
- —order-by-primary
- Указание параметра приводит к тому. что каждая таблица сортируется по первичному ключу или первому уникальному индексу.
- —port, -P
- Номер TCP порта, используемого для подключения к хосту.
- —protocol={TCP|SOCKET|PIPE|MEMORY}
- Параметр позволяет задать протокол подключения к серверу.
- —quick, -q
- Позволяет начать формирование дампа, не дожидаясь полной загрузки данных с сервера и экономя тем самым память.
- —quote-names, -Q
- Помещает имена баз данных, таблиц и столбцов в обратные апострофы `. Начиная с MySQL 4.1, данный параметр включен по умолчанию.
- —replace
- Добавляет ключевое слово REPLACE в оператор INSERT. Данный параметр впервые появился в MySQL 5.1.3.
- —result-file=/path/to/file, -r /path/to/file
- Параметр направляет дамп в файл file. Этот параметр особенно удобен в Windows, без использования командной строки. когда можно перенаправить результат в файл при помощи последовательностей > и >>.
- —routines, -R
- Данный параметр создает дамп хранимых процедур и функций. Доступен с MySQL 5.1.2.
- —single-transaction
- Параметр создает дамп в виде одной транзакции.
- —skip-comments
- Данный параметр позволяет подавить вывод в дамп дополнительной информации.
- —socket=/path/to/socket, -S /path/to/socket
- Файл сокета для подсоединения к localhost.
- —tab=/path/, -T /path/
- При использовании этого параметра в каталоге path для каждой таблицы создаются два отдельных файла: tbl_name.sql, содержащий оператор CREATE TABLE, и tbl_name.txt, который содержит данные таблиц, разделенные символом табуляции. Формат данных может быть переопределен явно с помощью параметров —fields-xxx и —lines-xxx.
- —tables
- Перекрывает действия параметра —databases (-B). Все аргументы, следующие за этим параметром, трактуются как имена таблиц.
- —triggers
- Создается дамп триггеров. Этот параметр включен по умолчанию. для его отключения следует использовать параметр —skip-triggers.
- —events, -E
- Создается дамп событий. Смотрите MySQL Event Scheduler или встроенный диспетчер событий в MySQL.
- —tz-utc
- при использовании данного параметра в дамп будет добавлен оператор вида SET TIME_ZONE=’+00:00′, который позволит обмениваться дампа в различных временных зонах.
- —verbose, -v
- Расширенный режим вывода. Вывод более детальной информации о работе программы.
- —version, -V
- Вывести информацию о версии программы.
- —where=’where-condition’, -w ‘where-condition’
- Выполнить дамп только выбранных записей. Обратите внимание, что кавычки обязательны.
- —xml, -X
- Представляет дамп базы данных в виде XML.
- —first-slave, -x
- Блокирует все таблицы во всех базах данных.
- —debug=…, -#
- Отслеживать прохождение программы (для отладки).
- —help
- Вывести справочную информацию и выйти из программы.
Еще пару слов о бекапе в MySQL
mysqlhotcopy для MyISAM
Для быстрого резервирования БД с типом таблиц ISAM и MyISAM можно использовать «mysqlhotcopy», которая скопирует файлы *.frm, *.MYD и *.MYI:
# mysqlhotcopy db_name /path/to/dir
Для InnoDB не подойдет данный способ, потому что при этом типе не обязательно все файлы будут храниться в директории базы данных.
xtrabackup для InnoDB
Для InnoDB есть xtrabackup, рекомендую посмотреть!
UPD: XtraBackup — резервное копирование для innoDBБин-лог и репликации
Для репликации «mysqldump» не предназначена, для этого есть бин-лог (—log-bin):
# mysqlbinlog binlog.[0-9]* | mysql
Для полной репликации необходимо вести бин-лог с самого начала работы БД, то есть еще до создания структур и данных.
Резервирование данныс в MySQL 6.x
С версии MySQL 6.x доступен online-backup, вот слайд объясняющий нововведения:
MYSQLDUMP(1) | MySQL Database System | MYSQLDUMP(1) |
NAME
mysqldump — a database backup program
SYNOPSIS
mysqldump [options]
[db_name [tbl_name …]]
DESCRIPTION
The mysqldump client utility performs logical backups,
producing a set of SQL statements that can be executed to reproduce the
original database object definitions and table data. It dumps one or more
MySQL databases for backup or transfer to another SQL server. The
mysqldump command can also generate output in CSV, other delimited
text, or XML format.
Tip
Consider using the MySQL Shell dump utilities[1], which
provide parallel dumping with multiple threads, file compression, and
progress information display, as well as cloud features such as Oracle Cloud
Infrastructure Object Storage streaming, and MySQL Database Service
compatibility checks and modifications. Dumps can be easily imported into a
MySQL Server instance or a MySQL Database Service DB System using the
MySQL Shell load dump utilities[2]. Installation instructions for
MySQL Shell can be found here[3].
•Performance and Scalability Considerations
•Invocation Syntax
•Option Syntax — Alphabetical Summary
•Connection Options
•Option-File Options
•DDL Options
•Debug Options
•Help Options
•Internationalization Options
•Replication Options
•Format Options
•Filtering Options
•Performance Options
•Transactional Options
•Option Groups
•Examples
•Restrictions
mysqldump requires at least the SELECT privilege for dumped
tables, SHOW VIEW for dumped views, TRIGGER for dumped triggers, LOCK TABLES
if the —single-transaction option is not used, and (as of MySQL
8.0.21) PROCESS if the —no-tablespaces option is not used. Certain options
might require other privileges as noted in the option descriptions.
To reload a dump file, you must have the privileges required to
execute the statements that it contains, such as the appropriate CREATE
privileges for objects created by those statements.
mysqldump output can include ALTER DATABASE statements that
change the database collation. These may be used when dumping stored
programs to preserve their character encodings. To reload a dump file
containing such statements, the ALTER privilege for the affected database is
required.
Note
A dump made using PowerShell on Windows with output redirection
creates a file that has UTF-16 encoding:
mysqldump [options] > dump.sql
However, UTF-16 is not permitted as a connection character set
(see the section called “Impermissible Client Character
Sets”), so the dump file cannot be loaded correctly. To work around
this issue, use the —result-file option, which creates the output in
ASCII format:
mysqldump [options] --result-file=dump.sql
It is not recommended to load a dump file when GTIDs are enabled
on the server (gtid_mode=ON), if your dump file includes system tables.
mysqldump issues DML instructions for the system tables which use the
non-transactional MyISAM storage engine, and this combination is not
permitted when GTIDs are enabled. Performance and Scalability
Considerations
mysqldump advantages include the convenience and flexibility of
viewing or even editing the output before restoring. You can clone databases
for development and DBA work, or produce slight variations of an existing
database for testing. It is not intended as a fast or scalable solution for
backing up substantial amounts of data. With large data sizes, even if the
backup step takes a reasonable time, restoring the data can be very slow
because replaying the SQL statements involves disk I/O for insertion, index
creation, and so on.
For large-scale backup and restore, a physical backup is more
appropriate, to copy the data files in their original format so that they
can be restored quickly.
If your tables are primarily InnoDB tables, or if you have a mix
of InnoDB and MyISAM tables, consider using mysqlbackup, which is
available as part of MySQL Enterprise. This tool provides high performance
for InnoDB backups with minimal disruption; it can also back up tables from
MyISAM and other storage engines; it also provides a number of convenient
options to accommodate different backup scenarios. See Section 30.2,
“MySQL Enterprise Backup Overview”.
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, use the
—skip-opt option instead of the —opt or
—extended-insert option.
For additional information about mysqldump, see
Section 7.4, “Using mysqldump for Backups”. Invocation
Syntax
There are in general three ways to use mysqldump—in
order to dump a set of one or more tables, a set of one or more complete
databases, or an entire MySQL server—as shown here:
mysqldump [options] db_name [tbl_name ...] mysqldump [options] --databases db_name ... mysqldump [options] --all-databases
To dump entire databases, do not name any tables following
db_name, or use the —databases or —all-databases
option.
To see a list of the options your version of mysqldump
supports, issue the command mysqldump —help. Option Syntax —
Alphabetical Summary
mysqldump supports the following options, which can be
specified on the command line or in the [mysqldump] and [client] groups of
an option file. For information about option files used by MySQL programs,
see Section 4.2.2.2, “Using Option Files”. Connection
Options
The mysqldump command logs into a MySQL server to extract
information. The following options specify how to connect to the MySQL
server, either on the same machine or a remote system.
•—bind-address=ip_address On
a computer having multiple network interfaces, use this option to select which
interface to use for connecting to the MySQL server.
•—compress, -C Compress all
information sent between the client and the server if possible. See
Section 4.2.8, “Connection Compression Control”.
As of MySQL 8.0.18, this option is deprecated. Expect it to be
removed in a future version of MySQL. See the section called
“Configuring Legacy Connection Compression”.
•—compression-algorithms=value
The permitted compression algorithms for connections to the server. The
available algorithms are the same as for the protocol_compression_algorithms
system variable. The default value is uncompressed.
For more information, see Section 4.2.8, “Connection
Compression Control”.
This option was added in MySQL 8.0.18.
•—default-auth=plugin A hint
about which client-side authentication plugin to use. See
Section 6.2.17, “Pluggable Authentication”.
•—enable-cleartext-plugin Enable the
mysql_clear_password cleartext authentication plugin. (See
Section 6.4.1.4, “Client-Side Cleartext Pluggable
Authentication”.)
•—get-server-public-key Request from the
server the public key required for RSA key pair-based password exchange. This
option applies to clients that authenticate with the caching_sha2_password
authentication plugin. For that plugin, the server does not send the public
key unless requested. This option is ignored for accounts that do not
authenticate with that plugin. It is also ignored if RSA-based password
exchange is not used, as is the case when the client connects to the server
using a secure connection.
If —server-public-key-path=file_name is
given and specifies a valid public key file, it takes precedence over
—get-server-public-key.
For information about the caching_sha2_password plugin, see
Section 6.4.1.2, “Caching SHA-2 Pluggable
Authentication”.
•—host=host_name, -h
host_name Dump data from the MySQL server on the given host.
The default host is localhost.
•—login-path=name Read
options from the named login path in the .mylogin.cnf login path file. A
“login path” is an option group containing options that specify
which MySQL server to connect to and which account to authenticate as. To
create or modify a login path file, use the mysql_config_editor
utility. See mysql_config_editor(1).
For additional information about this and other option-file
options, see Section 4.2.2.3, “Command-Line Options that
Affect Option-File Handling”.
•—password[=password],
-p[password] The password of the MySQL account
used for connecting to the server. The password value is optional. If not
given, mysqldump prompts for one. If given, there must be no
space between —password= or -p and the password following
it. If no password option is specified, the default is to send no password.
Specifying a password on the command line should be considered
insecure. To avoid giving the password on the command line, use an option
file. See Section 6.1.2.1, “End-User Guidelines for Password
Security”.
To explicitly specify that there is no password and that
mysqldump should not prompt for one, use the —skip-password
option.
•—password1[=pass_val]
The password for multifactor authentication factor 1 of the MySQL account used
for connecting to the server. The password value is optional. If not given,
mysqldump prompts for one. If given, there must be no space
between —password1= and the password following it. If no password
option is specified, the default is to send no password.
Specifying a password on the command line should be considered
insecure. To avoid giving the password on the command line, use an option
file. See Section 6.1.2.1, “End-User Guidelines for Password
Security”.
To explicitly specify that there is no password and that
mysqldump should not prompt for one, use the —skip-password1
option.
—password1 and —password are synonymous, as are
—skip-password1 and —skip-password.
•—password2[=pass_val]
The password for multifactor authentication factor 2 of the MySQL account used
for connecting to the server. The semantics of this option are similar to the
semantics for —password1; see the description of that option for
details.
•—password3[=pass_val]
The password for multifactor authentication factor 3 of the MySQL account used
for connecting to the server. The semantics of this option are similar to the
semantics for —password1; see the description of that option for
details.
•—pipe, -W On Windows, connect to
the server using a named pipe. This option applies only if the server was
started with the named_pipe system variable enabled to support named-pipe
connections. In addition, the user making the connection must be a member of
the Windows group specified by the named_pipe_full_access_group system
variable.
•—plugin-dir=dir_name The
directory in which to look for plugins. Specify this option if the
—default-auth option is used to specify an authentication plugin but
mysqldump does not find it. See Section 6.2.17,
“Pluggable Authentication”.
•—port=port_num, -P
port_num For TCP/IP connections, the port number to
use.
•—protocol={TCP|SOCKET|PIPE|MEMORY} The
transport protocol to use for connecting to the server. It is useful when the
other connection parameters normally result in use of a protocol other than
the one you want. For details on the permissible values, see
Section 4.2.7, “Connection Transport Protocols”.
•—server-public-key-path=file_name
The path name to a file in PEM format containing a client-side copy of the
public key required by the server for RSA key pair-based password exchange.
This option applies to clients that authenticate with the sha256_password or
caching_sha2_password authentication plugin. This option is ignored for
accounts that do not authenticate with one of those plugins. It is also
ignored if RSA-based password exchange is not used, as is the case when the
client connects to the server using a secure connection.
If —server-public-key-path=file_name is
given and specifies a valid public key file, it takes precedence over
—get-server-public-key.
For sha256_password, this option applies only if MySQL was built
using OpenSSL.
For information about the sha256_password and
caching_sha2_password plugins, see Section 6.4.1.3, “SHA-256
Pluggable Authentication”, and Section 6.4.1.2,
“Caching SHA-2 Pluggable Authentication”.
•—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.
On Windows, this option applies only if the server was started
with the named_pipe system variable enabled to support named-pipe
connections. In addition, the user making the connection must be a member of
the Windows group specified by the named_pipe_full_access_group system
variable.
•—ssl* Options that begin with
—ssl specify whether to connect to the server using encryption and
indicate where to find SSL keys and certificates. See the section called
“Command Options for Encrypted Connections”.
•—ssl-fips-mode={OFF|ON|STRICT} Controls
whether to enable FIPS mode on the client side. The —ssl-fips-mode
option differs from other —ssl-xxx options in that it is
not used to establish encrypted connections, but rather to affect which
cryptographic operations to permit. See Section 6.8, “FIPS
Support”.
These —ssl-fips-mode values are permitted:
•OFF: Disable FIPS mode.
•ON: Enable FIPS mode.
•STRICT: Enable “strict” FIPS
mode.
Note
If the OpenSSL FIPS Object Module is not available, the only permitted value for
—ssl-fips-mode is OFF. In this case, setting —ssl-fips-mode to
ON or STRICT causes the client to produce a warning at startup and to operate
in non-FIPS mode.
•—tls-ciphersuites=ciphersuite_list
The permissible ciphersuites for encrypted connections that use TLSv1.3. The
value is a list of one or more colon-separated ciphersuite names. The
ciphersuites that can be named for this option depend on the SSL library used
to compile MySQL. For details, see Section 6.3.2, “Encrypted
Connection TLS Protocols and Ciphers”.
This option was added in MySQL 8.0.16.
•—tls-version=protocol_list
The permissible TLS protocols for encrypted connections. The value is a list
of one or more comma-separated protocol names. The protocols that can be named
for this option depend on the SSL library used to compile MySQL. For details,
see Section 6.3.2, “Encrypted Connection TLS Protocols and
Ciphers”.
•—user=user_name, -u
user_name The user name of the MySQL account to use for
connecting to the server.
If you are using the Rewriter plugin with MySQL 8.0.31 or later,
you should grant this user the SKIP_QUERY_REWRITE privilege.
•—zstd-compression-level=level
The compression level to use for connections to the server that use the zstd
compression algorithm. The permitted levels are from 1 to 22, with larger
values indicating increasing levels of compression. The default zstd
compression level is 3. The compression level setting has no effect on
connections that do not use zstd compression.
For more information, see Section 4.2.8, “Connection
Compression Control”.
This option was added in MySQL 8.0.18.
Option-File Options
These options are used to control which option files to read.
•—defaults-extra-file=file_name
Read this option file after the global option file but (on Unix) before the
user option file. If the file does not exist or is otherwise inaccessible, an
error occurs. If file_name is not an absolute path name, it is
interpreted relative to the current directory.
For additional information about this and other option-file
options, see Section 4.2.2.3, “Command-Line Options that
Affect Option-File Handling”.
•—defaults-file=file_name
Use only the given option file. If the file does not exist or is otherwise
inaccessible, an error occurs. If file_name is not an absolute path
name, it is interpreted relative to the current directory.
Exception: Even with —defaults-file, client programs read
.mylogin.cnf.
For additional information about this and other option-file
options, see Section 4.2.2.3, “Command-Line Options that
Affect Option-File Handling”.
•—defaults-group-suffix=str
Read not only the usual option groups, but also groups with the usual names
and a suffix of str. For example, mysqldump normally reads the
[client] and [mysqldump] groups. If this option is given as
—defaults-group-suffix=_other, mysqldump also reads the
[client_other] and [mysqldump_other] groups.
For additional information about this and other option-file
options, see Section 4.2.2.3, “Command-Line Options that
Affect Option-File Handling”.
•—no-defaults Do not read any option
files. If program startup fails due to reading unknown options from an option
file, —no-defaults can be used to prevent them from being read.
The exception is that the .mylogin.cnf file is read in all cases,
if it exists. This permits passwords to be specified in a safer way than on
the command line even when —no-defaults is used. To create
.mylogin.cnf, use the mysql_config_editor utility. See
mysql_config_editor(1).
For additional information about this and other option-file
options, see Section 4.2.2.3, “Command-Line Options that
Affect Option-File Handling”.
•—print-defaults Print the program name
and all options that it gets from option files.
For additional information about this and other option-file
options, see Section 4.2.2.3, “Command-Line Options that
Affect Option-File Handling”.
DDL Options
Usage scenarios for mysqldump include setting up an entire
new MySQL instance (including database tables), and replacing data inside an
existing instance with existing databases and tables. The following options
let you specify which things to tear down and set up when restoring a dump,
by encoding various DDL statements within the dump file.
•—add-drop-database Write 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.
Note
In MySQL 8.0, the mysql schema is considered a system schema that cannot be
dropped by end users. If —add-drop-database is used with
—all-databases or with —databases where the list of schemas to
be dumped includes mysql, the dump file contains a DROP DATABASE `mysql`
statement that causes an error when the dump file is reloaded.
Instead, to use —add-drop-database, use —databases
with a list of schemas to be dumped, where the list does not include
mysql.
•—add-drop-table Write a DROP TABLE
statement before each CREATE TABLE statement.
•—add-drop-trigger Write a DROP TRIGGER
statement before each CREATE TRIGGER statement.
•—all-tablespaces, -Y Adds to a
table dump all SQL statements needed to create any tablespaces used by an NDB
table. This information is not otherwise included in the output from
mysqldump. This option is currently relevant only to NDB Cluster
tables.
•—no-create-db, -n Suppress 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 create each dumped table.
Note
This option does not exclude statements creating log file groups or
tablespaces from mysqldump output; however, you can use the
—no-tablespaces option for this purpose.
•—no-tablespaces, -y This option
suppresses all CREATE LOGFILE GROUP and CREATE TABLESPACE statements in the
output of mysqldump.
•—replace Write REPLACE statements rather
than INSERT statements.
Debug Options
The following options print debugging information, encode
debugging information in the dump file, or let the dump operation proceed
regardless of potential problems.
•—allow-keywords Permit creation of column
names that are keywords. This works by prefixing each column name with the
table name.
•—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.
•—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.
This option is available only if MySQL was built using
WITH_DEBUG. MySQL release binaries provided by Oracle are not
built using this option.
•—debug-check Print some debugging
information when the program exits.
This option is available only if MySQL was built using
WITH_DEBUG. MySQL release binaries provided by Oracle are not
built using this option.
•—debug-info Print debugging information
and memory and CPU usage statistics when the program exits.
This option is available only if MySQL was built using
WITH_DEBUG. MySQL release binaries provided by Oracle are not
built using this option.
•—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.
•—force, -f Ignore all errors;
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.
If the —ignore-error option is also given to ignore
specific errors, —force takes precedence.
•—log-error=file_name Log
warnings and errors by appending them to the named file. The default is to do
no logging.
•—skip-comments See the description for
the —comments option.
•—verbose, -v Verbose mode. Print
more information about what the program does.
Help Options
The following options display information about the
mysqldump command itself.
•—help, -? Display a help message
and exit.
•—version, -V Display version
information and exit.
Internationalization Options
The following options change how the mysqldump command
represents character data with national language settings.
•—character-sets-dir=dir_name
The directory where character sets are installed. See Section 10.15,
“Character Set Configuration”.
•—default-character-set=charset_name
Use charset_name as the default character set. See
Section 10.15, “Character Set Configuration”. If no
character set is specified, mysqldump uses utf8mb4.
•—no-set-names, -N Turns off the
—set-charset setting, the same as specifying
—skip-set-charset.
•—set-charset Write SET NAMES
default_character_set to the output. This option is enabled by default.
To suppress the SET NAMES statement, use —skip-set-charset.
Replication Options
The mysqldump command is frequently used to create an empty
instance, or an instance including data, on a replica server in a
replication configuration. The following options apply to dumping and
restoring data on replication source servers and replicas.
•—apply-replica-statements From MySQL
8.0.26, use —apply-replica-statements, and before MySQL 8.0.26, use
—apply-slave-statements. Both options have the same effect. For a
replica dump produced with the —dump-replica or —dump-slave
option, the options add a STOP REPLICA (or before MySQL 8.0.22, STOP SLAVE)
statement before the statement with the binary log coordinates, and a START
REPLICA statement at the end of the output.
•—apply-slave-statements Use this option
before MySQL 8.0.26 rather than —apply-replica-statements. Both
options have the same effect.
•—delete-source-logs From MySQL 8.0.26,
use —delete-source-logs, and before MySQL 8.0.26, use
—delete-master-logs. Both options have the same effect. On a
replication source server, the options delete the binary logs by sending a
PURGE BINARY LOGS statement to the server after performing the dump operation.
The options require the RELOAD privilege as well as privileges sufficient to
execute that statement. The options automatically enable —source-data
or —master-data.
•—delete-master-logs Use this option
before MySQL 8.0.26 rather than —delete-source-logs. Both options have
the same effect.
•—dump-replica[=value]
From MySQL 8.0.26, use —dump-replica, and before MySQL 8.0.26, use
—dump-slave. Both options have the same effect. The options are
similar to —source-data, except that they are used to dump a replica
server to produce a dump file that can be used to set up another server as a
replica that has the same source as the dumped server. The options cause the
dump output to include a CHANGE REPLICATION SOURCE TO statement (from MySQL
8.0.23) or CHANGE MASTER TO statement (before MySQL 8.0.23) that indicates the
binary log coordinates (file name and position) of the dumped replica’s
source. The CHANGE REPLICATION SOURCE TO statement reads the values of
Relay_Master_Log_File and Exec_Master_Log_Pos from the SHOW REPLICA STATUS
output and uses them for SOURCE_LOG_FILE and SOURCE_LOG_POS respectively.
These are the replication source server coordinates from which the replica
starts replicating.
Note
Inconsistencies in the sequence of transactions from the relay log which have
been executed can cause the wrong position to be used. See
Section 17.5.1.34, “Replication and Transaction
Inconsistencies” for more information.
—dump-replica or —dump-slave cause the coordinates from the
source to be used rather than those of the dumped server, as is done by the
—source-data or —master-data option. In addition, specifying
this option causes the —source-data or —master-data option to
be overridden, if used, and effectively ignored.
Warning
—dump-replica and —dump-slave should not be used if the server
where the dump is going to be applied uses gtid_mode=ON and
SOURCE_AUTO_POSITION=1 or MASTER_AUTO_POSITION=1.
The option value is handled the same way as for —source-data. Setting no
value or 1 causes a CHANGE REPLICATION SOURCE TO statement (from MySQL 8.0.23)
or CHANGE MASTER TO statement (before MySQL 8.0.23) to be written to the dump.
Setting 2 causes the statement to be written but encased in SQL comments. It
has the same effect as —source-data in terms of enabling or disabling
other options and in how locking is handled.
—dump-replica and —dump-slave cause
mysqldump to stop the replication SQL thread before the dump and
restart it again after.
—dump-replica and —dump-slave send a SHOW REPLICA
STATUS statement to the server to obtain information, so they require
privileges sufficient to execute that statement.
—apply-replica-statements and
—include-source-host-port options can be used in conjunction with
—dump-replica and —dump-slave.
•—dump-slave[=value]
Use this option before MySQL 8.0.26 rather than —dump-replica. Both
options have the same effect.
•—include-source-host-port From MySQL
8.0.26, use —include-source-host-port, and before MySQL 8.0.26, use
—include-master-host-port. Both options have the same effect. The
options add the SOURCE_HOST | MASTER_HOST and SOURCE_PORT | MASTER_PORT
options for the host name and TCP/IP port number of the replica’s source, to
the CHANGE REPLICATION SOURCE TO statement (from MySQL 8.0.23) or CHANGE
MASTER TO statement (before MySQL 8.0.23) in a replica dump produced with the
—dump-replica or —dump-slave option.
•—include-master-host-port Use this option
before MySQL 8.0.26 rather than —include-source-host-port. Both
options have the same effect.
•—source-data[=value]
From MySQL 8.0.26, use —source-data, and before MySQL 8.0.26, use
—master-data. Both options have the same effect. The options are used
to dump a replication source server to produce a dump file that can be used to
set up another server as a replica of the source. The options cause the dump
output to include a CHANGE REPLICATION SOURCE TO statement (from MySQL 8.0.23)
or CHANGE MASTER TO statement (before MySQL 8.0.23) that indicates the binary
log coordinates (file name and position) of the dumped server. These are the
replication source server coordinates from which the replica should start
replicating after you load the dump file into the replica.
If the option value is 2, the CHANGE REPLICATION SOURCE TO |
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.
—source-data and —master-data send a SHOW MASTER
STATUS statement to the server to obtain information, so they require
privileges sufficient to execute that statement. This option also requires
the RELOAD privilege and the binary log must be enabled.
—source-data and —master-data automatically turn
off —lock-tables. They also turn on —lock-all-tables, unless
—single-transaction also is specified, in which case, a global read
lock is acquired only for a short time at the beginning of the dump (see the
description for —single-transaction). In all cases, any action on
logs happens at the exact moment of the dump.
It is also possible to set up a replica by dumping an existing
replica of the source, using the —dump-replica or
—dump-slave option, which overrides —source-data and
—master-data and causes them to be ignored.
•—master-data[=value]
Use this option before MySQL 8.0.26 rather than —source-data. Both
options have the same effect.
•—set-gtid-purged=value This
option is for servers that use GTID-based replication (gtid_mode=ON). It
controls the inclusion of a SET @@GLOBAL.gtid_purged statement in the dump
output, which updates the value of gtid_purged on a server where the dump file
is reloaded, to add the GTID set from the source server’s gtid_executed system
variable. gtid_purged holds the GTIDs of all transactions that have been
applied on the server, but do not exist on any binary log file on the server.
mysqldump therefore adds the GTIDs for the transactions that were
executed on the source server, so that the target server records these
transactions as applied, although it does not have them in its binary logs.
—set-gtid-purged also controls the inclusion of a SET
@@SESSION.sql_log_bin=0 statement, which disables binary logging while the
dump file is being reloaded. This statement prevents new GTIDs from being
generated and assigned to the transactions in the dump file as they are
executed, so that the original GTIDs for the transactions are used.
If you do not set the —set-gtid-purged option, the default
is that a SET @@GLOBAL.gtid_purged statement is included in the dump output
if GTIDs are enabled on the server you are backing up, and the set of GTIDs
in the global value of the gtid_executed system variable is not empty. A SET
@@SESSION.sql_log_bin=0 statement is also included if GTIDs are enabled on
the server.
You can either replace the value of gtid_purged with a specified
GTID set, or add a plus sign (+) to the statement to append a specified GTID
set to the GTID set that is already held by gtid_purged. The SET
@@GLOBAL.gtid_purged statement recorded by mysqldump includes a plus
sign (+) in a version-specific comment, such that MySQL 8.0 (and later) adds
the GTID set from the dump file to the existing gtid_purged value.
It is important to note that the value that is included by
mysqldump for the SET @@GLOBAL.gtid_purged statement includes the
GTIDs of all transactions in the gtid_executed set on the server, even those
that changed suppressed parts of the database, or other databases on the
server that were not included in a partial dump. This can mean that after
the gtid_purged value has been updated on the server where the dump file is
replayed, GTIDs are present that do not relate to any data on the target
server. If you do not replay any further dump files on the target server,
the extraneous GTIDs do not cause any problems with the future operation of
the server, but they make it harder to compare or reconcile GTID sets on
different servers in the replication topology. If you do replay a further
dump file on the target server that contains the same GTIDs (for example,
another partial dump from the same origin server), any SET
@@GLOBAL.gtid_purged statement in the second dump file fails. In this case,
either remove the statement manually before replaying the dump file, or
output the dump file without the statement.
Using this option with the —single-transaction option can
lead to inconsistencies in the output. If —set-gtid-purged=ON is
required, it can be used with —lock-all-tables, but this can prevent
parallel queries while mysqldump is being run.
If the SET @@GLOBAL.gtid_purged statement would not have the
desired result on your target server, you can exclude the statement from the
output, or (from MySQL 8.0.17) include it but comment it out so that it is
not actioned automatically. You can also include the statement but manually
edit it in the dump file to achieve the desired result.
The possible values for the —set-gtid-purged option are as
follows:
AUTO
The default value. If GTIDs are enabled on the server you
are backing up and gtid_executed is not empty, SET @@GLOBAL.gtid_purged is
added to the output, containing the GTID set from gtid_executed. If GTIDs are
enabled, SET @@SESSION.sql_log_bin=0 is added to the output. If GTIDs are not
enabled on the server, the statements are not added to the output.
OFF
SET @@GLOBAL.gtid_purged is not added to the output, and
SET @@SESSION.sql_log_bin=0 is not added to the output. For a server where
GTIDs are not in use, use this option or AUTO. Only use this option for a
server where GTIDs are in use if you are sure that the required GTID set is
already present in gtid_purged on the target server and should not be changed,
or if you plan to identify and add any missing GTIDs manually.
ON
If GTIDs are enabled on the server you are backing up,
SET @@GLOBAL.gtid_purged is added to the output (unless gtid_executed is
empty), and SET @@SESSION.sql_log_bin=0 is added to the output. An error
occurs if you set this option but GTIDs are not enabled on the server. For a
server where GTIDs are in use, use this option or AUTO, unless you are sure
that the GTIDs in gtid_executed are not needed on the target server.
COMMENTED
Available from MySQL 8.0.17. If GTIDs are enabled on the
server you are backing up, SET @@GLOBAL.gtid_purged is added to the output
(unless gtid_executed is empty), but it is commented out. This means that the
value of gtid_executed is available in the output, but no action is taken
automatically when the dump file is reloaded. SET @@SESSION.sql_log_bin=0 is
added to the output, and it is not commented out. With COMMENTED, you can
control the use of the gtid_executed set manually or through automation. For
example, you might prefer to do this if you are migrating data to another
server that already has different active databases.
Format Options
The following options specify how to represent the entire dump
file or certain kinds of data in the dump file. They also control whether
certain optional information is written to the dump file.
•—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 only permitted value for this option is ansi, which has the same
meaning as the corresponding option for setting the server SQL mode. See
Section 5.1.11, “Server SQL Modes”.
•—complete-insert, -c Use complete
INSERT statements that include column names.
•—create-options Include all
MySQL-specific table options in the CREATE TABLE statements.
•—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. See Section 13.2.7, “LOAD DATA Statement”.
•—hex-blob Dump binary columns using
hexadecimal notation (for example, ‘abc’ becomes 0x616263). The affected data
types are BINARY, VARBINARY, BLOB types, BIT, all spatial data types, and
other non-binary data types when used with the binary character set.
•—lines-terminated-by=… This option is
used with the —tab option and has the same meaning as the
corresponding LINES clause for LOAD DATA. See Section 13.2.7,
“LOAD DATA Statement”.
•—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.
•—result-file=file_name,
-r file_name Direct output to the named file. The result
file is created and its previous contents overwritten, even if an error occurs
while generating the dump.
This option should be used on Windows to prevent newline n
characters from being converted to rn carriage return/newline
sequences.
•—show-create-skip-secondary-engine=value
Excludes the SECONDARY ENGINE clause from CREATE TABLE statements. It does so
by enabling the show_create_table_skip_secondary_engine system variable for
the duration of the dump operation. Alternatively, you can enable the
show_create_table_skip_secondary_engine system variable prior to using
mysqldump.
This option was added in MySQL 8.0.18. Attempting a
mysqldump operation with the
—show-create-skip-secondary-engine option on a release prior to
MySQL 8.0.18 that does not support the
show_create_table_skip_secondary_engine variable causes an error.
•—tab=dir_name, -T
dir_name 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. Because the server creates *.txt files in the
directory that you specify, the directory must be writable by the server and
the MySQL account that you use must have the FILE privilege. Because
mysqldump creates *.sql in the same directory, it must be writable by
your system login account.
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.
•—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.
•—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> |
(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 CLIENT OPTIONS”.)
XML output from mysqldump includes the XML namespace, as
shown here:
$> 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>
Filtering Options
The following options control which kinds of schema objects are
written to the dump file: by category, such as triggers or events; by name,
for example, choosing which databases and tables to dump; or even filtering
rows from the table data using a WHERE clause.
•—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.
Note
See the —add-drop-database description for information about an
incompatibility of that option with —all-databases.
Prior to MySQL 8.0, the —routines and —events options for
mysqldump and mysqlpump were not required to include stored
routines and events when using the —all-databases option: The dump
included the mysql system database, and therefore also the mysql.proc and
mysql.event tables containing stored routine and event definitions. As of
MySQL 8.0, the mysql.event and mysql.proc tables are not used. Definitions for
the corresponding objects are stored in data dictionary tables, but those
tables are not dumped. To include stored routines and events in a dump made
using —all-databases, use the —routines and —events
options explicitly.
•—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.
This option may be used to dump the performance_schema database,
which normally is not dumped even with the —all-databases option.
(Also use the —skip-lock-tables option.)
Note
See the —add-drop-database description for information about an
incompatibility of that option with —databases.
•—events, -E Include Event
Scheduler events for the dumped databases in the output. This option requires
the EVENT privileges for those databases.
The output generated by using —events contains CREATE
EVENT statements to create the events.
•—ignore-error=error[,error]…
Ignore the specified errors. The option value is a list of comma-separated
error numbers specifying the errors to ignore during mysqldump
execution. If the —force option is also given to ignore all errors,
—force takes precedence.
•—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.
•—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).
•—routines, -R Include stored
routines (procedures and functions) for the dumped databases in the output.
This option requires the global SELECT privilege.
The output generated by using —routines contains CREATE
PROCEDURE and CREATE FUNCTION statements to create the routines.
•—skip-generated-invisible-primary-key
This option is available beginning with MySQL 8.0.30, and causes generated
invisible primary keys to be excluded from the output. For more information,
see Section 13.1.20.11, “Generated Invisible Primary
Keys”.
•—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.
To be able to dump a table’s triggers, you must have the TRIGGER
privilege for the table.
Multiple triggers are permitted. mysqldump dumps triggers
in activation order so that when the dump file is reloaded, triggers are
created in the same activation order. However, if a mysqldump dump
file contains multiple triggers for a table that have the same trigger event
and action time, an error occurs for attempts to load the dump file into an
older server that does not support multiple triggers. (For a workaround, see
Downgrade Notes[4]; you can convert triggers to be compatible with
older servers.)
•—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"
Performance Options
The following options are the most relevant for the performance
particularly of the restore operations. For large data sets, restore
operation (processing the INSERT statements in the dump file) is the most
time-consuming part. When it is urgent to restore data quickly, plan and
test the performance of this stage in advance. For restore times measured in
hours, you might prefer an alternative backup and restore solution, such as
MySQL Enterprise Backup for InnoDB-only and mixed-use databases.
Performance is also affected by the transactional options,
primarily for the dump operation.
•—column-statistics Add ANALYZE TABLE
statements to the output to generate histogram statistics for dumped tables
when the dump file is reloaded. This option is disabled by default because
histogram generation for large tables can take a long time.
•—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.
•—extended-insert, -e Write INSERT
statements using multiple-row syntax that includes several VALUES lists. This
results in a smaller dump file and speeds up inserts when the file is
reloaded.
•—insert-ignore Write INSERT IGNORE
statements rather than INSERT statements.
•—max-allowed-packet=value
The maximum size of the buffer for client/server communication. The default is
24MB, the maximum is 1GB.
•—mysqld-long-query-time=value
Set the session value of the long_query_time system variable. Use this option,
which is available from MySQL 8.0.30, if you want to increase the time allowed
for mysqldump’s queries before they are logged to the slow query
log file. mysqldump performs a full table scan, which means its queries
can often exceed a global long_query_time setting that is useful for regular
queries. The default global setting is 10 seconds.
You can use —mysqld-long-query-time to specify a session
value from 0 (meaning that every query from mysqldump is logged to
the slow query log) to 31536000, which is 365 days in seconds. For
mysqldump’s option, you can only specify whole seconds. When
you do not specify this option, the server’s global setting applies
to mysqldump’s queries.
•—net-buffer-length=value
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 bytes long. If you increase this variable, ensure
that the MySQL server net_buffer_length system variable has a value at least
this large.
•—network-timeout, -M Enable large
tables to be dumped by setting —max-allowed-packet to its maximum
value and network read and write timeouts to a large value. This option is
enabled by default. To disable it, use —skip-network-timeout.
•—opt This option, enabled by default, is
shorthand for the combination of —add-drop-table —add-locks
—create-options —disable-keys —extended-insert
—lock-tables —quick —set-charset. It gives a fast dump
operation and produces a dump file that can be reloaded into a MySQL server
quickly.
Because the —opt option is enabled by default, you only
specify its converse, the —skip-opt to turn off several default
settings. See the discussion of mysqldump option groups for information
about selectively enabling or disabling a subset of the options affected by
—opt.
•—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.
•—skip-opt See the description for the
—opt option.
Transactional Options
The following options trade off the performance of the dump
operation, against the reliability and consistency of the exported data.
•—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 8.2.5.1, “Optimizing
INSERT Statements”.
•—flush-logs, -F Flush the MySQL
server log files before starting the dump. This option requires the RELOAD
privilege. If you use this option in combination with the
—all-databases option, the logs are flushed for each database
dumped. The exception is when using —lock-all-tables,
—source-data or —master-data, or —single-transaction.
In these cases, the logs are flushed only once, corresponding to the moment
that all tables are locked by FLUSH TABLES WITH READ LOCK. If you want your
dump and the log flush to happen at exactly the same moment, you should use
—flush-logs together with —lock-all-tables,
—source-data or —master-data, or
—single-transaction.
•—flush-privileges Add a FLUSH PRIVILEGES
statement to the dump output 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.
Because the dump file contains a FLUSH PRIVILEGES statement,
reloading the file requires privileges sufficient to execute that
statement.
Note
For upgrades to MySQL 5.7 or higher from older versions, do not use
—flush-privileges. For upgrade instructions in this case, see
Section 2.11.4, “Changes in MySQL 8.0”.
•—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 permit 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.
Some options, such as —opt, automatically enable
—lock-tables. If you want to override this, use
—skip-lock-tables at the end of the option list.
•—no-autocommit Enclose the INSERT
statements for each dumped table within SET autocommit = 0 and COMMIT
statements.
•—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 makes the dump operation take considerably longer.
•—shared-memory-base-name=name
On Windows, the shared-memory name to use for connections made using shared
memory to a local server. The default value is MYSQL. The shared-memory name
is case-sensitive.
This option applies only if the server was started with the
shared_memory system variable enabled to support shared-memory
connections.
•—single-transaction This option sets the
transaction isolation mode to REPEATABLE READ and 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 START TRANSACTION 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.
Using —single-transaction together with the
—set-gtid-purged option is not recommended; doing so can lead to
inconsistencies in the output of mysqldump.
To dump large tables, combine the —single-transaction
option with the —quick option.
Option Groups
•The —opt option turns on several settings
that work together to perform a fast dump operation. All of these settings are
on by default, because —opt is on by default. Thus you rarely if ever
specify —opt. Instead, you can turn these settings off as a group by
specifying —skip-opt, the optionally re-enable certain settings by specifying
the associated options later on the command line.
•The —compact option turns off several
settings that control whether optional statements and comments appear in the
output. Again, you can follow this option with other options that re-enable
certain settings, or turn all the settings on by using the —skip-compact
form.
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.
Examples
To make a backup of an entire database:
mysqldump db_name > backup-file.sql
To load the dump file back into the server:
mysql db_name < backup-file.sql
Another way to reload the dump file:
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:
mysqldump --opt db_name | mysql --host=remote_host -C db_name
You can dump several databases with one command:
mysqldump --databases db_name1 [db_name2 ...] > my_databases.sql
To dump all databases, use the —all-databases option:
mysqldump --all-databases > all_databases.sql
For InnoDB tables, mysqldump provides a way of making an
online backup:
mysqldump --all-databases --master-data --single-transaction > all_databases.sql or from MySQL 8.0.26: mysqldump --all-databases --source-data --single-transaction > all_databases.sql
This backup acquires a global read lock on all tables (using FLUSH
TABLES WITH READ LOCK) at the beginning of the dump. As soon as this lock
has been acquired, the binary log coordinates are read and the lock is
released. If long updating statements are running when the FLUSH statement
is issued, the MySQL server may get stalled until those statements finish.
After that, the dump becomes lock free and does not disturb reads and writes
on the tables. If the update statements that the MySQL server receives are
short (in terms of execution time), the initial lock period should not be
noticeable, even with many updates.
For point-in-time recovery (also known as
“roll-forward,” when you need to restore an old backup and
replay the changes that happened since that backup), it is often useful to
rotate the binary log (see Section 5.4.4, “The Binary
Log”) or at least know the binary log coordinates to which the dump
corresponds:
mysqldump --all-databases --master-data=2 > all_databases.sql or from MySQL 8.0.26: mysqldump --all-databases --source-data=2 > all_databases.sql
Or:
mysqldump --all-databases --flush-logs --master-data=2 > all_databases.sql or from MySQL 8.0.26: mysqldump --all-databases --flush-logs --source-data=2 > all_databases.sql
The —source-data or —master-data option can be
used simultaneously with the —single-transaction option, 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.
For more information on making backups, see Section 7.2,
“Database Backup Methods”, and Section 7.3,
“Example Backup and Recovery Strategy”.
•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
disabling of indexes and table locking, use —skip-opt
—disable-keys —lock-tables.
Restrictions
mysqldump does not dump the performance_schema or sys
schema by default. To dump any of these, name them explicitly on the command
line. You can also name them with the —databases option. For
performance_schema, also use the —skip-lock-tables option.
mysqldump does not dump the INFORMATION_SCHEMA schema.
mysqldump does not dump InnoDB CREATE TABLESPACE
statements.
mysqldump does not dump the NDB Cluster ndbinfo information
database.
mysqldump includes statements to recreate the general_log
and slow_query_log tables for dumps of the mysql database. Log table
contents are not dumped.
If you encounter problems backing up views due to insufficient
privileges, see Section 25.9, “Restrictions on Views”
for a workaround.
COPYRIGHT
Copyright © 1997, 2022, Oracle and/or its affiliates.
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.
- MySQL Shell dump utilities
- 2.
- MySQL Shell load dump utilities
- 3.
- here
- 4.
- Downgrade Notes
SEE ALSO
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/.
Oracle Corporation (http://dev.mysql.com/).