ERROR 1025 (HY000): Error on rename of to
刚才又一个一不小心,在Slave上执行了更改数据库schema的操作,结果是这台服务器在mmm_control中的状态就变成了:REPLICATION_FA
刚才又一个一不小心,,在Slave上执行了更改数据库schema的操作,结果是这台服务器在mmm_control中的状态就变成了:REPLICATION_FAIL。先通过writer执行了同样的操作,保证服务器正常运行,然后就考虑把这台slave重新拉回到mysql-mmm阵营。
看了一下执行的增量SQL文件,它进行的主要操作有:为一个表A添加三个字段A1、A2、A3,增加一个新表B,为表C增加一个字段C1,其中C1为外键CF1(关键点是:外键的名字和字段的名字相同,假设都为C1),关联B的主键B1。所以接下来要进行的就是回滚这些操作:
1、删除A表中的新增的三个字段:
2、删除C表中的外键CF1,然后删除C1:
执行这条语句得到了下面的错误信息:
ERROR 1025 (HY000): Error on rename of './db1/C' to './db1/#sql2-31ef-2c2d4e' (errno: 152)
那么直接删除字段C1呢:
ALTER TABLE C DROP COLUMN C1;
得到的错误信息是:
ERROR 1025 (HY000): Error on rename of './db1/#sql-31ef_2c2d4e' to './db1/C' (errno: 150)
问题的原因在上面已经提示到了:外键和字段使用了同样的名字。
解决方法:
1、先通过
找到创建外键的语句:
2、 通过CONSTRAINT的名字删除外键:
然后再执行其他后续操作就可以了。
解决上面的问题后,通过“START SLAVE”重新启动slave线程,过一会儿再去查看mmm_control的状态,发现该slave已经回来了。
参考资料:

Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

Notepad++7.3.1
Easy-to-use and free code editor

SublimeText3 Chinese version
Chinese version, very easy to use

Zend Studio 13.0.1
Powerful PHP integrated development environment

Dreamweaver CS6
Visual web development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

Hot Topics

Full table scanning may be faster in MySQL than using indexes. Specific cases include: 1) the data volume is small; 2) when the query returns a large amount of data; 3) when the index column is not highly selective; 4) when the complex query. By analyzing query plans, optimizing indexes, avoiding over-index and regularly maintaining tables, you can make the best choices in practical applications.

InnoDB's full-text search capabilities are very powerful, which can significantly improve database query efficiency and ability to process large amounts of text data. 1) InnoDB implements full-text search through inverted indexing, supporting basic and advanced search queries. 2) Use MATCH and AGAINST keywords to search, support Boolean mode and phrase search. 3) Optimization methods include using word segmentation technology, periodic rebuilding of indexes and adjusting cache size to improve performance and accuracy.

Yes, MySQL can be installed on Windows 7, and although Microsoft has stopped supporting Windows 7, MySQL is still compatible with it. However, the following points should be noted during the installation process: Download the MySQL installer for Windows. Select the appropriate version of MySQL (community or enterprise). Select the appropriate installation directory and character set during the installation process. Set the root user password and keep it properly. Connect to the database for testing. Note the compatibility and security issues on Windows 7, and it is recommended to upgrade to a supported operating system.

The difference between clustered index and non-clustered index is: 1. Clustered index stores data rows in the index structure, which is suitable for querying by primary key and range. 2. The non-clustered index stores index key values and pointers to data rows, and is suitable for non-primary key column queries.

MySQL is an open source relational database management system. 1) Create database and tables: Use the CREATEDATABASE and CREATETABLE commands. 2) Basic operations: INSERT, UPDATE, DELETE and SELECT. 3) Advanced operations: JOIN, subquery and transaction processing. 4) Debugging skills: Check syntax, data type and permissions. 5) Optimization suggestions: Use indexes, avoid SELECT* and use transactions.

MySQL supports four index types: B-Tree, Hash, Full-text, and Spatial. 1.B-Tree index is suitable for equal value search, range query and sorting. 2. Hash index is suitable for equal value searches, but does not support range query and sorting. 3. Full-text index is used for full-text search and is suitable for processing large amounts of text data. 4. Spatial index is used for geospatial data query and is suitable for GIS applications.

In MySQL database, the relationship between the user and the database is defined by permissions and tables. The user has a username and password to access the database. Permissions are granted through the GRANT command, while the table is created by the CREATE TABLE command. To establish a relationship between a user and a database, you need to create a database, create a user, and then grant permissions.

MySQL and MariaDB can coexist, but need to be configured with caution. The key is to allocate different port numbers and data directories to each database, and adjust parameters such as memory allocation and cache size. Connection pooling, application configuration, and version differences also need to be considered and need to be carefully tested and planned to avoid pitfalls. Running two databases simultaneously can cause performance problems in situations where resources are limited.
