/** * sql server 2000 安全 */ -- 禁止访问注册表扩展存储过程 , 与此同时删除此扩展过程对应的 xpstar.dll 文件(删除该文件影响任务调度) use master revoke execute on xp_regread from dbo revoke execute on xp_regread from guest -- 禁止 public 对 s
/**
* sql server 2000 安全
*/
-- 禁止访问注册表扩展存储过程,与此同时删除此扩展过程对应的xpstar.dll文件(删除该文件影响任务调度)
usemaster
revokeexecuteon xp_regread from dbo
revokeexecuteon xp_regread from guest
-- 禁止public对sp_runwebtask的执行权限
usemaster
revokeexecuteon master.dbo.sp_runwebtask frompublic
-- 禁止public对创建sql代理任务的存储过程的访问权限
use msdb
revokeexecuteon msdb.dbo.sp_add_job frompublic
revokeexecuteon msdb.dbo.sp_add_jobstep frompublic
revokeexecuteon msdb.dbo.sp_add_jobserver frompublic
revokeexecuteon msdb.dbo.sp_start_job frompublic
-- 启用登录审计 操作步骤 企业管理器-右击【服务器图标】-属性-安全性-审核级别选中【全部】-重启
-- 启用C2审计模式 需重启
usemaster
exec sp_configure 'show advanced option','1'
reconfigure
exec sp_configure 'c2 audit mode','1'
reconfigure
-- 删除guest帐户
usemaster
go
sp_dropuser guest
go

ACID attributes include atomicity, consistency, isolation and durability, and are the cornerstone of database design. 1. Atomicity ensures that the transaction is either completely successful or completely failed. 2. Consistency ensures that the database remains consistent before and after a transaction. 3. Isolation ensures that transactions do not interfere with each other. 4. Persistence ensures that data is permanently saved after transaction submission.

MySQL is not only a database management system (DBMS) but also closely related to programming languages. 1) As a DBMS, MySQL is used to store, organize and retrieve data, and optimizing indexes can improve query performance. 2) Combining SQL with programming languages, embedded in Python, using ORM tools such as SQLAlchemy can simplify operations. 3) Performance optimization includes indexing, querying, caching, library and table division and transaction management.

MySQL uses SQL commands to manage data. 1. Basic commands include SELECT, INSERT, UPDATE and DELETE. 2. Advanced usage involves JOIN, subquery and aggregate functions. 3. Common errors include syntax, logic and performance issues. 4. Optimization tips include using indexes, avoiding SELECT* and using LIMIT.

MySQL is an efficient relational database management system suitable for storing and managing data. Its advantages include high-performance queries, flexible transaction processing and rich data types. In practical applications, MySQL is often used in e-commerce platforms, social networks and content management systems, but attention should be paid to performance optimization, data security and scalability.

The relationship between SQL and MySQL is the relationship between standard languages and specific implementations. 1.SQL is a standard language used to manage and operate relational databases, allowing data addition, deletion, modification and query. 2.MySQL is a specific database management system that uses SQL as its operating language and provides efficient data storage and management.

InnoDB uses redologs and undologs to ensure data consistency and reliability. 1.redologs record data page modification to ensure crash recovery and transaction persistence. 2.undologs records the original data value and supports transaction rollback and MVCC.

Key metrics for EXPLAIN commands include type, key, rows, and Extra. 1) The type reflects the access type of the query. The higher the value, the higher the efficiency, such as const is better than ALL. 2) The key displays the index used, and NULL indicates no index. 3) rows estimates the number of scanned rows, affecting query performance. 4) Extra provides additional information, such as Usingfilesort prompts that it needs to be optimized.

Usingtemporary indicates that the need to create temporary tables in MySQL queries, which are commonly found in ORDERBY using DISTINCT, GROUPBY, or non-indexed columns. You can avoid the occurrence of indexes and rewrite queries and improve query performance. Specifically, when Usingtemporary appears in EXPLAIN output, it means that MySQL needs to create temporary tables to handle queries. This usually occurs when: 1) deduplication or grouping when using DISTINCT or GROUPBY; 2) sort when ORDERBY contains non-index columns; 3) use complex subquery or join operations. Optimization methods include: 1) ORDERBY and GROUPB


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