DELETE_TABLE_NAME = "" DELETE_TABLE_KEY = "" DELETE_CONDITION = "" DELETE_ROWS_PER_BATCH = 10000 SLEEP_SECOND_PER_BATCH = 0.5 # MySQL Connection Config Default_MySQL_Host = '192.168.166.169' Default_MySQL_Port = 3358 Default_MySQL_User = "mysql_admin" Default_MySQL_Password = 'mysql@...
ndb_delete_alldeletes all rows from the givenNDBtable. In some cases, this can be much faster thanDELETEor evenTRUNCATE TABLE. Usage ndb_delete_all-cconnection_stringtbl_name-ddb_name This deletes all rows from the table namedtbl_namein the database nameddb_name. It is exactly equivalent...
], 字段2 类型2 [约束] )engine=innodb default charset=utf8; 查看建表语句 Show create table 表名; 删除表 drop table 表名; 修改表结构(添加字段,修改字段 ,删除字段) 添加字段 alter table 表名 add 字段名 字段类型 字段约束; 字段添加的位置(first 第一列 after 列名 那一列后面) 修改字段 ①不...
SELECT*FROM Main WHERE ...;--just the rows you want to keep RENAME TABLE main TO Old, New TO Main; DROP TABLE Old;-- Space freed up here 可通过:ALTER TABLE table_name REMOVE PARTITIONING删除分区,而不会删除相应的数据 参考: 1)https://dev.mysql.com/doc/refman/5.7/en/alter-table-part...
rows列:死亡预警 显示扫描行数,超过1000行就要警惕! 某金融系统优化后,扫描行数从10万→8行 Extra列:隐藏病症 ❗ Using temporary:临时表地狱 ❗ Using filesort:文件排序大坑 ❗ Using where:索引失效警告 急救方案:<br/>--错误示范SELECT * FROM user WHERE age>20 ORDER BY name;--优化方案(name+...
9. show index from table_name ##查看表的索引情况。 10. select * from STATISTICS where table_name='XXX'\G ##查看表的统计信息。 11. select @@max_allowed_packet; ## 查询定义的packet大小。 12. show master status;##查看master状态。可以查看 最后(最新)一个binlog日志的编号名称,及其最后一个...
[root@mysql8_3 test]# mysql -uroot -pmysql> use test;Reading table information for completion of table and column namesYou can turn off this feature to get a quicker startup with -Amysql> import table from '/u01/mysql3308/tmp/tmyisam_392.sdi'; Query OK, 0 rows affected (0.02 sec...
"table": "`yp_user`", "field": "gender", "equals": "1", "null_rejecting": false } ] }, { "rows_estimation": [ { "table": "`yp_user`", "range_analysis": { "table_scan": { "rows": 3100, "cost": 719.1 }, "potential_range_indexes": [ ...
含义：区分简单select和复杂select。作用：了解查询的类型，有助于判断查询的复杂度和优化方向。table列：含义：显示查询中访问的表名或别名。作用：明确指出查询涉及的表，便于后续分析和优化。type列：含义：访问类型，表示MySQL在找到所需行时访问表的方法。按效率从低到高排序，如ALL、index、range、ref...
1.先查询出库中的所有表,“db”是数据库名称 SELECT CONCAT('truncate table ',TABLE_NAME,';') AS a FROM INFORMATION_SCHEMA.TABLES...WHERE TABLE_SCHEMA = 'db' ; 2.得到所有表后,复制,粘贴,运行,见下图 ...