对MySQL dump内部工作机制的举例分析

发布时间：2023-11-01 13:23:34 所属栏目：MySql教程来源：

导读：小编给大家分享一下mysqldump内部实现原理的示例分析，相信大部分人都还不怎么了解，因此分享这篇文章给大家参考一下，希望大家阅读完这篇文章后大有收获，下面让我们一起去了解一下吧！我们可以通过打开general log

小编给大家分享一下mysqldump内部实现原理的示例分析，相信大部分人都还不怎么了解，因此分享这篇文章给大家参考一下，希望大家阅读完这篇文章后大有收获，下面让我们一起去了解一下吧！

我们可以通过打开general log，查看mysqldump全库备份时执行的命令来了解mysqldump背后的原理。

打开general log

mysql> set global general_log=on;

其中，general log的存放路径可通过以下命令查看

mysql> show variables like '%general_log_file%';

总结

1、--master-data产生如下，会导致mysqldump期间无法执行DDL和DML，而且执行mysqldump之前表有锁，则mysqldump会等待，导出结果是发生mysqldump这一刻的数据

FLUSH /*!40101 LOCAL */ TABLES和FLUSH TABLES WITH READ LOCK和SHOW MASTER STATUS

2、--lock-all-tables产生如下，会导致mysqldump期间无法执行DDL和DML，而且执行mysqldump之前表有锁，则mysqldump会等待，导出结果是发生mysqldump这一刻的数据

FLUSH TABLES和FLUSH TABLES WITH READ LOCK

3、--master-data和--lock-all-tables同时使用时，效果和--master-data一致

4、--single-transaction产生如下，mysqldump期间不影响DML和DDL，但是mysqldump本身可能受DDL影响而报错退出，mysqldump之前表有锁，mysqldump也不会等待，导出结果是发生mysqldump这一刻的数据

UNLOCK TABLES，SET SESSION TRANSACTION ISOLATION LEVEL REPEATABLE READ，SAVEPOINT，ROLLBACK TO SAVEPOINT，RELEASE SAVEPOINT

5、--skip-lock-tables不产生任何LOCK，mysqldump期间不影响DML和DDL，但是mysqldump本身可能受DDL影响而报错退出，mysqldump之前表有锁，mysqldump也不会等待，导出结果不是mysqldump这一刻的数据，而是导那张表的开始时刻就是该表的数据(比如导A表是8:00,则导出过程要一个小时，导出结果也是8:00的数据，导B表是9:00,则导出过程要一个小时，B的导出结果也是9:00的数据)，和oracle 的expdp相似。

6、默认导出产生如下，会导致mysqldump期间,正在执行导出的库无法执行DDL和DML，没有在执行导出的库可以执行DDL和DML，mysqldump之前表有锁，mysqldump也不会等待，导出结果不是发生mysqldump这一刻的数据，而是导那个库的开始时刻就是那个库的数据(比如导A库是8:00,则导出过程要一个小时，A的导出结果也是8:00的数据，导B库是9:00,则导出过程要一个小时，B的导出结果也是9:00的数据)。

LOCK TABLES `table1` READ /*!32311 LOCAL */,`table2` READ /*!32311 LOCAL */

UNLOCK TABLES

7、生成建库语句，生成建表语句，备份的核心语句（该语句查询到表table1的所有数据，在备份文件中会生成相应的insert语句。其中SQL_NO_CACHE的作用是查询的结果并不会缓存到查询缓存中），分别如下

SHOW CREATE DATABASE IF NOT EXISTS `test1`

show create table `table1`

SELECT /*!40001 SQL_NO_CACHE */ * FROM `table1`

--master-data日志如下

有FLUSH /*!40101 LOCAL */ TABLES和FLUSH TABLES WITH READ LOCK和SHOW MASTER STATUS

没有任何UNLOCK

mysqldump --master-data=2 --databases test1 > /home/test1_2.sql

2019-01-06T06:29:59.361208Z 4 Connect root@localhost on using Socket

2019-01-06T06:29:59.361337Z 4 Query /*!40100 SET @@SQL_MODE='' */

2019-01-06T06:29:59.361434Z 4 Query /*!40103 SET TIME_ZONE='+00:00' */

2019-01-06T06:29:59.361558Z 4 Query FLUSH /*!40101 LOCAL */ TABLES

2019-01-06T06:29:59.369450Z 4 Query FLUSH TABLES WITH READ LOCK

2019-01-06T06:29:59.369580Z 4 Query SHOW VARIABLES LIKE 'gtid\_mode'

2019-01-06T06:29:59.372284Z 4 Query SHOW MASTER STATUS

2019-01-06T06:29:59.372533Z 4 Query SELECT ...

...

2019-01-06T06:29:59.375795Z 4 Query SHOW VARIABLES LIKE 'ndbinfo\_version'

2019-01-06T06:29:59.378605Z 4 Init DB test1

2019-01-06T06:29:59.378670Z 4 Query SHOW CREATE DATABASE IF NOT EXISTS `test1`

2019-01-06T06:29:59.378767Z 4 Query show tables

2019-01-06T06:29:59.379070Z 4 Query show table status like 'table1'

2019-01-06T06:29:59.379457Z 4 Query SET SQL_QUOTE_SHOW_CREATE=1

2019-01-06T06:29:59.379555Z 4 Query SET SESSION character_set_results = 'binary'

2019-01-06T06:29:59.379649Z 4 Query show create table `table1`

2019-01-06T06:29:59.379778Z 4 Query SET SESSION character_set_results = 'utf8'

2019-01-06T06:29:59.379940Z 4 Query show fields from `table1`

2019-01-06T06:29:59.380463Z 4 Query show fields from `table1`

2019-01-06T06:29:59.380933Z 4 Query SELECT /*!40001 SQL_NO_CACHE */ * FROM `table1`

2019-01-06T06:29:59.381225Z 4 Query SET SESSION character_set_results = 'binary'

2019-01-06T06:29:59.381323Z 4 Query use `test1`

2019-01-06T06:29:59.381416Z 4 Query select @@collation_database

2019-01-06T06:29:59.381546Z 4 Query SHOW TRIGGERS LIKE 'table1'

2019-01-06T06:29:59.382209Z 4 Query SET SESSION character_set_results = 'utf8'

2019-01-06T06:29:59.382309Z 4 Query show table status like 'table2'

2019-01-06T06:29:59.382597Z 4 Query SET SQL_QUOTE_SHOW_CREATE=1

2019-01-06T06:29:59.382670Z 4 Query SET SESSION character_set_results = 'binary'

2019-01-06T06:29:59.382746Z 4 Query show create table `table2`

2019-01-06T06:29:59.382848Z 4 Query SET SESSION character_set_results = 'utf8'

2019-01-06T06:29:59.382983Z 4 Query show fields from `table2`

2019-01-06T06:29:59.383385Z 4 Query show fields from `table2`

2019-01-06T06:29:59.383782Z 4 Query SELECT /*!40001 SQL_NO_CACHE */ * FROM `table2`

2019-01-06T06:29:59.384125Z 4 Query SET SESSION character_set_results = 'binary'

2019-01-06T06:29:59.384223Z 4 Query use `test1`

2019-01-06T06:29:59.384312Z 4 Query select @@collation_database

2019-01-06T06:29:59.384430Z 4 Query SHOW TRIGGERS LIKE 'table2'

2019-01-06T06:29:59.385032Z 4 Query SET SESSION character_set_results = 'utf8'

2019-01-06T06:29:59.420821Z 4 Quit

--single-transaction日志如下

没有FLUSH /*!40101 LOCAL */ TABLES和FLUSH TABLES WITH READ LOCK

只有UNLOCK TABLES，SAVEPOINT，ROLLBACK TO SAVEPOINT，RELEASE SAVEPOINT

mysqldump --single-transaction --databases test1 > /home/test1_2.sql

2019-01-06T06:16:52.542170Z 8 Connect root@localhost on using Socket

2019-01-06T06:16:52.542314Z 8 Query /*!40100 SET @@SQL_MODE='' */

2019-01-06T06:16:52.542433Z 8 Query /*!40103 SET TIME_ZONE='+00:00' */

2019-01-06T06:16:52.542593Z 8 Query SET SESSION TRANSACTION ISOLATION LEVEL REPEATABLE READ

2019-01-06T06:16:52.542674Z 8 Query START TRANSACTION /*!40100 WITH CONSISTENT SNAPSHOT */

2019-01-06T06:16:52.542794Z 8 Query SHOW VARIABLES LIKE 'gtid\_mode'

2019-01-06T06:16:52.545877Z 8 Query UNLOCK TABLES

2019-01-06T06:16:52.546158Z 8 Query SELECT...

...

2019-01-06T06:16:52.550745Z 8 Query SHOW VARIABLES LIKE 'ndbinfo\_version'

2019-01-06T06:16:52.553711Z 8 Init DB test1

2019-01-06T06:16:52.553793Z 8 Query SHOW CREATE DATABASE IF NOT EXISTS `test1`

2019-01-06T06:16:52.553896Z 8 Query SAVEPOINT sp

2019-01-06T06:16:52.554040Z 8 Query show tables

2019-01-06T06:16:52.554281Z 8 Query show table status like 'table1'

2019-01-06T06:16:52.554665Z 8 Query SET SQL_QUOTE_SHOW_CREATE=1

2019-01-06T06:16:52.554766Z 8 Query SET SESSION character_set_results = 'binary'

2019-01-06T06:16:52.554862Z 8 Query show create table `table1`

2019-01-06T06:16:52.555144Z 8 Query SET SESSION character_set_results = 'utf8'

2019-01-06T06:16:52.555263Z 8 Query show fields from `table1`

2019-01-06T06:16:52.555766Z 8 Query show fields from `table1`

2019-01-06T06:16:52.556323Z 8 Query SELECT /*!40001 SQL_NO_CACHE */ * FROM `table1`

2019-01-06T06:16:52.556585Z 8 Query SET SESSION character_set_results = 'binary'

2019-01-06T06:16:52.556682Z 8 Query use `test1`

2019-01-06T06:16:52.556776Z 8 Query select @@collation_database

2019-01-06T06:16:52.556908Z 8 Query SHOW TRIGGERS LIKE 'table1'

2019-01-06T06:16:52.557623Z 8 Query SET SESSION character_set_results = 'utf8'

2019-01-06T06:16:52.557709Z 8 Query ROLLBACK TO SAVEPOINT sp

2019-01-06T06:16:52.557793Z 8 Query show table status like 'table2'

2019-01-06T06:16:52.558118Z 8 Query SET SQL_QUOTE_SHOW_CREATE=1

2019-01-06T06:16:52.558191Z 8 Query SET SESSION character_set_results = 'binary'

2019-01-06T06:16:52.558264Z 8 Query show create table `table2`

2019-01-06T06:16:52.558391Z 8 Query SET SESSION character_set_results = 'utf8'

2019-01-06T06:16:52.558481Z 8 Query show fields from `table2`

2019-01-06T06:16:52.558904Z 8 Query show fields from `table2`

2019-01-06T06:16:52.559413Z 8 Query SELECT /*!40001 SQL_NO_CACHE */ * FROM `table2`

2019-01-06T06:16:52.559580Z 8 Query SET SESSION character_set_results = 'binary'

2019-01-06T06:16:52.559653Z 8 Query use `test1`

2019-01-06T06:16:52.559726Z 8 Query select @@collation_database

2019-01-06T06:16:52.559858Z 8 Query SHOW TRIGGERS LIKE 'table2'

2019-01-06T06:16:52.560307Z 8 Query SET SESSION character_set_results = 'utf8'

2019-01-06T06:16:52.560378Z 8 Query ROLLBACK TO SAVEPOINT sp

2019-01-06T06:16:52.560465Z 8 Query RELEASE SAVEPOINT sp

2019-01-06T06:16:52.658772Z 8 Quit

--skip-lock-tables日志如下

没有FLUSH /*!40101 LOCAL */ TABLES和FLUSH TABLES WITH READ LOCK

也没有任何UNLOCK

mysqldump --skip-lock-tables --databases test2 > /home/test1_2.sql

2019-01-03T14:35:41.956739Z 7 Connect root@localhost on using Socket

2019-01-03T14:35:41.956875Z 7 Query /*!40100 SET @@SQL_MODE='' */

2019-01-03T14:35:41.956976Z 7 Query /*!40103 SET TIME_ZONE='+00:00' */

2019-01-03T14:35:41.957122Z 7 Query SHOW VARIABLES LIKE 'gtid\_mode'

2019-01-03T14:35:41.959794Z 7 Query SELECT ...

...

2019-01-03T14:35:41.965124Z 7 Query SHOW VARIABLES LIKE 'ndbinfo\_version'

2019-01-03T14:35:41.967453Z 7 Init DB test2

2019-01-03T14:35:41.967557Z 7 Query SHOW CREATE DATABASE IF NOT EXISTS `test2`

2019-01-03T14:35:41.967659Z 7 Query show tables

2019-01-03T14:35:41.967871Z 7 Query show table status like 't1'

2019-01-03T14:35:41.968196Z 7 Query SET SQL_QUOTE_SHOW_CREATE=1

2019-01-03T14:35:41.968279Z 7 Query SET SESSION character_set_results = 'binary'

2019-01-03T14:35:41.968359Z 7 Query show create table `t1`

2019-01-03T14:35:41.968468Z 7 Query SET SESSION character_set_results = 'utf8'

2019-01-03T14:35:41.968690Z 7 Query show fields from `t1`

2019-01-03T14:35:41.969127Z 7 Query show fields from `t1`

2019-01-03T14:35:41.969589Z 7 Query SELECT /*!40001 SQL_NO_CACHE */ * FROM `t1`

2019-01-03T14:35:41.969824Z 7 Query SET SESSION character_set_results = 'binary'

2019-01-03T14:35:41.969906Z 7 Query use `test2`

2019-01-03T14:35:41.969986Z 7 Query select @@collation_database

2019-01-03T14:35:41.970098Z 7 Query SHOW TRIGGERS LIKE 't1'

2019-01-03T14:35:41.970753Z 7 Query SET SESSION character_set_results = 'utf8'

2019-01-03T14:35:41.970855Z 7 Query show table status like 't2'

2019-01-03T14:35:41.971246Z 7 Query SET SQL_QUOTE_SHOW_CREATE=1

2019-01-03T14:35:41.971325Z 7 Query SET SESSION character_set_results = 'binary'

2019-01-03T14:35:41.971404Z 7 Query show create table `t2`

2019-01-03T14:35:41.971671Z 7 Query SET SESSION character_set_results = 'utf8'

2019-01-03T14:35:41.971807Z 7 Query show fields from `t2`

2019-01-03T14:35:41.972269Z 7 Query show fields from `t2`

2019-01-03T14:35:41.972777Z 7 Query SELECT /*!40001 SQL_NO_CACHE */ * FROM `t2`

默认备份日志如下

没有FLUSH /*!40101 LOCAL */ TABLES和FLUSH TABLES WITH READ LOCK

但是有LOCK TABLES，结尾有UNLOCK TABLES

mysqldump --databases test2 > /home/test1_2.sql

2019-01-03T14:38:19.276575Z 8 Connect root@localhost on using Socket

2019-01-03T14:38:19.276814Z 8 Query /*!40100 SET @@SQL_MODE='' */

2019-01-03T14:38:19.276918Z 8 Query /*!40103 SET TIME_ZONE='+00:00' */

2019-01-03T14:38:19.277065Z 8 Query SHOW VARIABLES LIKE 'gtid\_mode'

2019-01-03T14:38:19.279690Z 8 Query SELECT ...

...

2019-01-03T14:38:19.285033Z 8 Query SHOW VARIABLES LIKE 'ndbinfo\_version'

2019-01-03T14:38:19.287392Z 8 Init DB test2

2019-01-03T14:38:19.287461Z 8 Query SHOW CREATE DATABASE IF NOT EXISTS `test2`

2019-01-03T14:38:19.287559Z 8 Query show tables

2019-01-03T14:38:19.287886Z 8 Query LOCK TABLES `t1` READ /*!32311 LOCAL */,`t2` READ /*!32311 LOCAL */,`t3` READ /*!32311 LOCAL */,`t4` READ /*!32311 LOCAL */,`t7` READ /*!32311 LOCAL */

2019-01-03T14:38:19.288043Z 8 Query show table status like 't1'

2019-01-03T14:38:19.288403Z 8 Query SET SQL_QUOTE_SHOW_CREATE=1

2019-01-03T14:38:19.288488Z 8 Query SET SESSION character_set_results = 'binary'

2019-01-03T14:38:19.288569Z 8 Query show create table `t1`

2019-01-03T14:38:19.288714Z 8 Query SET SESSION character_set_results = 'utf8'

2019-01-03T14:38:19.288808Z 8 Query show fields from `t1`

2019-01-03T14:38:19.289236Z 8 Query show fields from `t1`

2019-01-03T14:38:19.289789Z 8 Query SELECT /*!40001 SQL_NO_CACHE */ * FROM `t1`

2019-01-03T14:38:19.290008Z 8 Query SET SESSION character_set_results = 'binary'

2019-01-03T14:38:19.290090Z 8 Query use `test2`

2019-01-03T14:38:19.290171Z 8 Query select @@collation_database

2019-01-03T14:38:19.290281Z 8 Query SHOW TRIGGERS LIKE 't1'

2019-01-03T14:38:19.290768Z 8 Query SET SESSION character_set_results = 'utf8'

2019-01-03T14:38:19.290869Z 8 Query show table status like 't2'

2019-01-03T14:38:19.291184Z 8 Query SET SQL_QUOTE_SHOW_CREATE=1

2019-01-03T14:38:19.291260Z 8 Query SET SESSION character_set_results = 'binary'

2019-01-03T14:38:19.291338Z 8 Query show create table `t2`

2019-01-03T14:38:19.291437Z 8 Query SET SESSION character_set_results = 'utf8'

2019-01-03T14:38:19.291528Z 8 Query show fields from `t2`

2019-01-03T14:38:19.292061Z 8 Query show fields from `t2`

2019-01-03T14:38:19.292454Z 8 Query SELECT /*!40001 SQL_NO_CACHE */ * FROM `t2`

2019-01-03T14:38:19.292612Z 8 Query SET SESSION character_set_results = 'binary'

...

2019-01-03T14:38:19.302719Z 8 Query UNLOCK TABLES

2019-01-03T14:38:19.306712Z 8 Quit

--lock-all-tables

产生FLUSH TABLES和FLUSH TABLES WITH READ LOCK

没有任何UNLOCK

mysqldump --lock-all-tables --databases test1 > /home/test1_2.sql

2019-01-06T06:47:17.614479Z 5 Connect root@localhost on using Socket

2019-01-06T06:47:17.614801Z 5 Query /*!40100 SET @@SQL_MODE='' */

2019-01-06T06:47:17.614922Z 5 Query /*!40103 SET TIME_ZONE='+00:00' */

2019-01-06T06:47:17.615074Z 5 Query FLUSH TABLES

2019-01-06T06:47:17.620471Z 5 Query FLUSH TABLES WITH READ LOCK

2019-01-06T06:47:17.620629Z 5 Query SHOW VARIABLES LIKE 'gtid\_mode'

2019-01-06T06:47:17.623672Z 5 Query SELECT ...

...

2019-01-06T06:47:17.626996Z 5 Query SHOW VARIABLES LIKE 'ndbinfo\_version'

2019-01-06T06:47:17.629714Z 5 Init DB test1

2019-01-06T06:47:17.629798Z 5 Query SHOW CREATE DATABASE IF NOT EXISTS `test1`

2019-01-06T06:47:17.629916Z 5 Query show tables

2019-01-06T06:47:17.630154Z 5 Query show table status like 'table1'

2019-01-06T06:47:17.630615Z 5 Query SET SQL_QUOTE_SHOW_CREATE=1

2019-01-06T06:47:17.630702Z 5 Query SET SESSION character_set_results = 'binary'

2019-01-06T06:47:17.630780Z 5 Query show create table `table1`

2019-01-06T06:47:17.630889Z 5 Query SET SESSION character_set_results = 'utf8'

2019-01-06T06:47:17.630979Z 5 Query show fields from `table1`

2019-01-06T06:47:17.631397Z 5 Query show fields from `table1`

2019-01-06T06:47:17.632023Z 5 Query SELECT /*!40001 SQL_NO_CACHE */ * FROM `table1`

2019-01-06T06:47:17.632286Z 5 Query SET SESSION character_set_results = 'binary'

2019-01-06T06:47:17.632384Z 5 Query use `test1`

2019-01-06T06:47:17.632479Z 5 Query select @@collation_database

2019-01-06T06:47:17.632668Z 5 Query SHOW TRIGGERS LIKE 'table1'

2019-01-06T06:47:17.633103Z 5 Query SET SESSION character_set_results = 'utf8'

2019-01-06T06:47:17.633202Z 5 Query show table status like 'table2'

2019-01-06T06:47:17.633489Z 5 Query SET SQL_QUOTE_SHOW_CREATE=1

2019-01-06T06:47:17.633713Z 5 Query SET SESSION character_set_results = 'binary'

2019-01-06T06:47:17.633811Z 5 Query show create table `table2`

2019-01-06T06:47:17.633937Z 5 Query SET SESSION character_set_results = 'utf8'

2019-01-06T06:47:17.634045Z 5 Query show fields from `table2`

2019-01-06T06:47:17.634532Z 5 Query show fields from `table2`

2019-01-06T06:47:17.635011Z 5 Query SELECT /*!40001 SQL_NO_CACHE */ * FROM `table2`

2019-01-06T06:47:17.635177Z 5 Query SET SESSION character_set_results = 'binary'

2019-01-06T06:47:17.635250Z 5 Query use `test1`

2019-01-06T06:47:17.635317Z 5 Query select @@collation_database

2019-01-06T06:47:17.635400Z 5 Query SHOW TRIGGERS LIKE 'table2'

2019-01-06T06:47:17.635962Z 5 Query SET SESSION character_set_results = 'utf8'

2019-01-06T06:47:17.639473Z 5 Quit

--lock-all-tables --master-data同时使用

mysqldump --lock-all-tables --master-data=2 --databases test1 > /home/test1_2.sql

2019-01-06T07:11:08.806918Z 10 Connect root@localhost on using Socket

2019-01-06T07:11:08.807047Z 10 Query /*!40100 SET @@SQL_MODE='' */

2019-01-06T07:11:08.807174Z 10 Query /*!40103 SET TIME_ZONE='+00:00' */

2019-01-06T07:11:08.807392Z 10 Query FLUSH /*!40101 LOCAL */ TABLES

2019-01-06T07:11:08.807499Z 10 Query FLUSH TABLES WITH READ LOCK

2019-01-06T07:11:08.807598Z 10 Query SHOW VARIABLES LIKE 'gtid\_mode'

2019-01-06T07:11:08.810307Z 10 Query SHOW MASTER STATUS

2019-01-06T07:11:08.810538Z 10 Query SELECT ...

...

2019-01-06T07:11:08.813490Z 10 Query SHOW VARIABLES LIKE 'ndbinfo\_version'

2019-01-06T07:11:08.815880Z 10 Init DB test1

2019-01-06T07:11:08.815948Z 10 Query SHOW CREATE DATABASE IF NOT EXISTS `test1`

2019-01-06T07:11:08.816048Z 10 Query show tables

2019-01-06T07:11:08.816379Z 10 Query show table status like 'table1'

2019-01-06T07:11:08.816703Z 10 Query SET SQL_QUOTE_SHOW_CREATE=1

2019-01-06T07:11:08.816787Z 10 Query SET SESSION character_set_results = 'binary'

2019-01-06T07:11:08.816868Z 10 Query show create table `table1`

2019-01-06T07:11:08.816977Z 10 Query SET SESSION character_set_results = 'utf8'

2019-01-06T07:11:08.817070Z 10 Query show fields from `table1`

2019-01-06T07:11:08.817533Z 10 Query show fields from `table1`

2019-01-06T07:11:08.817952Z 10 Query SELECT /*!40001 SQL_NO_CACHE */ * FROM `table1`

2019-01-06T07:11:08.818288Z 10 Query SET SESSION character_set_results = 'binary'

2019-01-06T07:11:08.818376Z 10 Query use `test1`

2019-01-06T07:11:08.818455Z 10 Query select @@collation_database

2019-01-06T07:11:08.818567Z 10 Query SHOW TRIGGERS LIKE 'table1'

2019-01-06T07:11:08.818996Z 10 Query SET SESSION character_set_results = 'utf8'

2019-01-06T07:11:08.819080Z 10 Query show table status like 'table2'

2019-01-06T07:11:08.819376Z 10 Query SET SQL_QUOTE_SHOW_CREATE=1

2019-01-06T07:11:08.819439Z 10 Query SET SESSION character_set_results = 'binary'

2019-01-06T07:11:08.819503Z 10 Query show create table `table2`

2019-01-06T07:11:08.819589Z 10 Query SET SESSION character_set_results = 'utf8'

2019-01-06T07:11:08.819664Z 10 Query show fields from `table2`

2019-01-06T07:11:08.819993Z 10 Query show fields from `table2`

2019-01-06T07:11:08.820434Z 10 Query SELECT /*!40001 SQL_NO_CACHE */ * FROM `table2`

2019-01-06T07:11:08.820578Z 10 Query SET SESSION character_set_results = 'binary'

2019-01-06T07:11:08.820644Z 10 Query use `test1`

2019-01-06T07:11:08.820707Z 10 Query select @@collation_database

2019-01-06T07:11:08.820789Z 10 Query SHOW TRIGGERS LIKE 'table2'

2019-01-06T07:11:08.821171Z 10 Query SET SESSION character_set_results = 'utf8'

2019-01-06T07:11:08.846442Z 10 Quit

SELECT ...

...

内如为

2019-01-01T06:16:52.546158Z 8 Query SELECT LOGFILE_GROUP_NAME, FILE_NAME, TOTAL_EXTENTS, INITIAL_SIZE, ENGINE, EXTRA FROM INFORMATION_SCHEMA.FILES WHERE FILE_TYPE = 'UNDO LOG' AND FILE_NAME IS NOT NULL AND LOGFILE_GROUP_NAME IS NOT NULL AND LOGFILE_GROUP_NAME IN (SELECT DISTINCT LOGFILE_GROUP_NAME FROM INFORMATION_SCHEMA.FILES WHERE FILE_TYPE = 'DATAFILE' AND TABLESPACE_NAME IN (SELECT DISTINCT TABLESPACE_NAME FROM INFORMATION_SCHEMA.PARTITIONS WHERE TABLE_SCHEMA IN ('test1'))) GROUP BY LOGFILE_GROUP_NAME, FILE_NAME, ENGINE ORDER BY LOGFILE_GROUP_NAME

2019-01-01T06:16:52.549144Z 8 Query SELECT DISTINCT TABLESPACE_NAME, FILE_NAME, LOGFILE_GROUP_NAME, EXTENT_SIZE, INITIAL_SIZE, ENGINE FROM INFORMATION_SCHEMA.FILES WHERE FILE_TYPE = 'DATAFILE' AND TABLESPACE_NAME IN (SELECT DISTINCT TABLESPACE_NAME FROM INFORMATION_SCHEMA.PARTITIONS WHERE TABLE_SCHEMA IN ('test1')) ORDER BY TABLESPACE_NAME, LOGFILE_GROUP_NAME

以上是“mysqldump内部实现原理的示例分析”这篇文章的所有内容，感谢各位的阅读！

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