--需要归档的数据量mysql admin@192.168.58.3:employees>selectcount(*)fromemployeeswherefirst_name='Anneke';+---+|count(*)|+---+|225|+---+1rowinsetTime:0.025s--执行归档操作# pt-archiver--source h=192.168.58.3,P=3306,u=admin,D=employees,t=employees,A=utf8 --dest h=192.168.58.3,P=3...
mysql> select * from for_delete; +---+---+ | id | name | +---+---+ | 1 | A | | 2 | B | | 3 | C | +---+---+ 3 rows in set (0.00 sec) mysql> delete from for_delete; Query OK, 3 rows affected (0.04 sec) mysql> insert for_delete (name) values ('D'); ...
#插入100W数据 mysql> call insert_user_data(1000000); Query OK, 0 rows affected (35.99 sec) #添加相关索引 mysql> alter table user add index idx_name(name), add index idx_phone(phone); Query OK, 0 rows affected (6.00 sec) Records: 0 Duplicates: 0 Warnings: 0 #表上索引统计信息 mysql...
A column value can't be deleted. It can be dropped. Or it can be set to null if it's defined in create table code as nullable, or it can be set to 0 if it's numeric or '' if it's a string. So in your case ... update xf_user set sonnb_xengallery_video_count=0; ....
1 row in set, 1 warning (0.00 sec) 1. 2. 3. 4. 5. 6. 7. 自动提交关闭: mysql> set autocommit=0; Query OK, 0 rows affected (0.00 sec) mysql> select @@autocommit; +---+ | @@autocommit | +---+ | 0 | +---+ 1 row in set ...
This deletes all rows from the table namedtbl_namein the database nameddb_name. It is exactly equivalent to executingTRUNCATEdb_name.tbl_namein MySQL. Options that can be used withndb_delete_allare shown in the following table. Additional descriptions follow the table. ...
最近,在脉脉上看到一个楼主提出的问题:MySQL数据量大时,delete操作无法命中索引;并且还附上了相关案例截图。 最终,楼主通过开启MySQL分析优化器追踪,定位到是优化器搞的鬼,它觉得花费时间太长。因为我这个是测试数据,究其原因是因为数据倾斜,导致计算出的数据占比较大、花费时间长。
TRANSACTION 272174, ACTIVE 0 sec fetching rows mysql tables in use 1, locked 1 LOCK WAIT 18 lock struct(s), heap size 1136, 58 row lock(s), undo log entries 41 MySQL thread id 298, OS thread handle 140425685493504, query id 5479767 172.18.70.114 root updating ...
MySQL DELETE JOIN with LEFT JOIN# We often use the LEFT JOIN clause in the SELECT statement to find rows in the left table that have or don’t have matching rows in the right table. We can also use the LEFT JOIN clause in the DELETE statement to delete rows in a table (left table...
Re: How to delete rows of a table through PHP? Richard Murphy August 07, 2013 02:54PM Sorry, you can't reply to this topic. It has been closed. Content reproduced on this site is the property of the respective copyright holders. It is not reviewed in advance by Oracle and does not...