about Undo Tablespace used High ?

最新推荐文章于 2025-07-06 18:23:34 发布
转载 最新推荐文章于 2025-07-06 18:23:34 发布 · 133 阅读 · 0 ·
CC 4.0 BY-SA版权
原文链接：http://www.cnblogs.com/lovewifelovelife/archive/2012/12/07/3295003.html

本文详细探讨了Undo表空间使用率高的原因及其对数据库性能的影响，提供了深入的分析和有效的解决策略。
aocu40057610
关注
oracle 扩容undo,【案例】Oracle RAC数据库undo使用率较高的解决思路办法
weixin_29189363的博客
04-02 623
天萃荷净Oracle研究中心案例分析：运维DBA反映Oracle数据库undo使用较大，结合案例分析undo使用问题。本站文章除注明转载外，均为本站原创： 转载自love wife & love life —Roger 的Oracle技术博客本文链接地址: about Undo Tablespace used High今天有朋友在问关于undo 使用很高的问题,这个问题其实很常见了,上次也...
Oracle UNDO 监控
Aamir 的专栏
08-02 2316
Oracle 10g及后续版本较以前版本有一新特性即自动调整undo retention时间，大大简便了管理，对于自动扩展（autoextend on）的undo表空间，参数undo_retention设置成为Oracle自动调节undo retention的最低阀值。对于非自动扩展（autoextend off），非guarantee 的undo 表空间，Oracle会根据undo表空间大小和v
Managing the Undo Tablespace
Tisty的兵工厂--新Blog:http://www.UbuntuSky.cn
09-17 1503
导读：　　This chapter describes how to manage the undo tablespace, which stores information used to roll back changes to the Oracle Database. It contains the following topics:　　See Also:　　Part III, "Au
undo tablespace的恢复， database能不关闭最好不要关闭
jnrjian的博客
07-06 745
Solution=========or not.ORis:complete".dropped.
ORACLE 闪回恢复区（Flashback recovery area）与undo tablespace
热门推荐
小傅同志的专栏
04-15 1万+
Flashback 技术是以Undo segment中的内容为基础的， 因此受限于UNDO_RETENTON参数。 要使用flashback 的特性，必须启用自动撤销管理表空间。 在Oracle 11g里又出了一个新特性：Oracle Flashback Data Archive. FDA通过将变化数据另外存储到创建的闪回归档区（Flashback Archive）中，以和undo区别开
Mysql undo
u013469501的博客
01-07 500
14.6.3.4 Undo Tablespaces Undo tablespaces contain undo logs, which are collections of undo log records that contain information about how to undo the latest change by a transaction to a clustered index record.Undo logs exist within undo log segments, ..
Undo
Murphyt的专栏
02-03 509
What Is Undo? The purpose of redo is recover your operation,on the contrary,the purpose of undo is undo your operation.For example,your TRANSACTION is failed or you regret for the operation,at this
About Oracle UNDOTBS%_TABLESPACE
你的世界是你创造的结果
03-23 234
Oracle UNDOTBS%_TABLESPACE认识 Redo中只会记录少量信息，这些信息足以重演事务；同样Undo中也只记录精简信息，这些信息足以撤销事务。具体来说： 1 对于INSERT操作，回滚段只需要记录插入记录的ROWID，如果回退，那么只需将该记录根据ROWID删除即可； 2 对于UPDATE操作，回滚段只需要记录被更新字段的旧值即可（前镜像），回退时通过旧值覆盖新值即可完成回滚...
oracle_基础八(Undo)
夜归人
04-03 520
Auto Undo Mgmt: Concepts 1.Undo data is managed using an UNDO tablespace. 2.You allocate one UNDO tablespace per instance with enough space for the workload of the instance. 3.The Oracle server aut
MySQL数据落盘原理(data page、redo log、undo log、binlog、xa-2pc等源码分析)
weixin_38597669的博客
05-17 1212
本文主要分析MySQL事务持久性相关的源码，比如undo,redo何时生成，如何落盘；redo和binlog如何基于xa-2pc落盘等等知识点。
2025-10-24T06:14:45.483589Z 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details). 2025-10-24T06:14:45.487190Z 0 [Note] C:\Program Files\MySQL\MySQL Server 5.7\bin\mysqld.exe (mysqld 5.7.43-log) starting as process 2792 ... 2025-10-24T06:14:45.499521Z 0 [Note] InnoDB: Mutexes and rw_locks use Windows interlocked functions 2025-10-24T06:14:45.500924Z 0 [Note] InnoDB: Uses event mutexes 2025-10-24T06:14:45.501775Z 0 [Note] InnoDB: _mm_lfence() and _mm_sfence() are used for memory barrier 2025-10-24T06:14:45.503093Z 0 [Note] InnoDB: Compressed tables use zlib 1.2.13 2025-10-24T06:14:45.509869Z 0 [Note] InnoDB: Number of pools: 1 2025-10-24T06:14:45.510876Z 0 [Note] InnoDB: Not using CPU crc32 instructions 2025-10-24T06:14:45.516358Z 0 [Note] InnoDB: Initializing buffer pool, total size = 4G, instances = 8, chunk size = 128M 2025-10-24T06:14:45.739511Z 0 [Note] InnoDB: Completed initialization of buffer pool 2025-10-24T06:14:45.866688Z 0 [Note] InnoDB: Highest supported file format is Barracuda. 2025-10-24T06:14:45.917325Z 0 [Note] InnoDB: Log scan progressed past the checkpoint lsn 1818072334033 2025-10-24T06:14:45.919665Z 0 [Note] InnoDB: Doing recovery: scanned up to log sequence number 1818072343203 2025-10-24T06:14:46.501026Z 0 [Note] InnoDB: Database was not shutdown normally! 2025-10-24T06:14:46.502853Z 0 [Note] InnoDB: Starting crash recovery. 2025-10-24T06:14:53.325953Z 0 [Note] InnoDB: Removed temporary tablespace data file: "ibtmp1" 2025-10-24T06:14:53.328050Z 0 [Note] InnoDB: Creating shared tablespace for temporary tables 2025-10-24T06:14:53.331419Z 0 [Note] InnoDB: Setting file '.\ibtmp1' size to 12 MB. Physically writing the file full; Please wait ... 2025-10-24T06:14:53.341449Z 0 [Note] InnoDB: File '.\ibtmp1' size is now 12 MB. 2025-10-24T06:14:53.377635Z 0 [Note] InnoDB: 96 redo rollback segment(s) found. 96 redo rollback segment(s) are active. 2025-10-24T06:14:53.379973Z 0 [Note] InnoDB: 32 non-redo rollback segment(s) are active. 2025-10-24T06:14:53.382232Z 0 [Note] InnoDB: Waiting for purge to start 2025-10-24T06:14:53.434201Z 0 [Note] InnoDB: page_cleaner: 1000ms intended loop took 7651ms. The settings might not be optimal. (flushed=0 and evicted=0, during the time.) 2025-10-24T06:14:53.434424Z 0 [Note] InnoDB: 5.7.43 started; log sequence number 1818072343203 2025-10-24T06:14:53.440369Z 0 [ERROR] InnoDB: Page [page id: space=26, page number=3] log sequence number 1818075015616 is in the future! Current system log sequence number 1818072347793. 2025-10-24T06:14:53.440496Z 0 [Note] InnoDB: Loading buffer pool(s) from D:\MySql\data\ib_buffer_pool 2025-10-24T06:14:53.444882Z 0 [ERROR] InnoDB: Your database may be corrupt or you may have copied the InnoDB tablespace but not the InnoDB log files. Please refer to http://dev.mysql.com/doc/refman/5.7/en/forcing-innodb-recovery.html for information about forcing recovery. 2025-10-24T06:14:53.454213Z 0 [ERROR] InnoDB: Page [page id: space=26, page number=2] log sequence number 1818075015133 is in the future! Current system log sequence number 1818072347793. 2025-10-24T06:14:53.457121Z 0 [ERROR] InnoDB: Your database may be corrupt or you may have copied the InnoDB tablespace but not the InnoDB log files. Please refer to http://dev.mysql.com/doc/refman/5.7/en/forcing-innodb-recovery.html for information about forcing recovery. 2025-10-24T06:14:53.459265Z 0 [ERROR] InnoDB: Page [page id: space=26, page number=13] log sequence number 1818075023156 is in the future! Current system log sequence number 1818072347793. 2025-10-24T06:14:53.459333Z 0 [Note] Plugin 'FEDERATED' is disabled. 2025-10-24T06:14:53.461391Z 0 [ERROR] InnoDB: Page [page id: space=26, page number=4] log sequence number 1818074852082 is in the future! Current system log sequence number 1818072347793. 2025-10-24T06:14:53.464302Z 0 [ERROR] InnoDB: Your database may be corrupt or you may have copied the InnoDB tablespace but not the InnoDB log files. Please refer to http://dev.mysql.com/doc/refman/5.7/en/forcing-innodb-recovery.html for information about forcing recovery. 2025-10-24T06:14:53.468966Z 0 [ERROR] InnoDB: Page [page id: space=26, page number=8883] log sequence number 1818075644951 is in the future! Current system log sequence number 1818072347793. 2025-10-24T06:14:53.469327Z 0 [ERROR] InnoDB: Your database may be corrupt or you may have copied the InnoDB tablespace but not the InnoDB log files. Please refer to http://dev.mysql.com/doc/refman/5.7/en/forcing-innodb-recovery.html for information about forcing recovery. 2025-10-24T06:14:53.478059Z 0 [ERROR] InnoDB: Your database may be corrupt or you may have copied the InnoDB tablespace but not the InnoDB log files. Please refer to http://dev.mysql.com/doc/refman/5.7/en/forcing-innodb-recovery.html for information about forcing recovery. 2025-10-24T06:14:53.481293Z 0 [ERROR] InnoDB: Page [page id: space=26, page number=5] log sequence number 1818074822726 is in the future! Current system log sequence number 1818072347793. 2025-10-24T06:14:53.488992Z 0 [ERROR] InnoDB: Your database may be corrupt or you may have copied the InnoDB tablespace but not the InnoDB log files. Please refer to http://dev.mysql.com/doc/refman/5.7/en/forcing-innodb-recovery.html for information about forcing recovery. 2025-10-24T06:14:53.493841Z 0 [ERROR] InnoDB: Page [page id: space=26, page number=8] log sequence number 1818073611600 is in the future! Current system log sequence number 1818072347793. 2025-10-24T06:14:53.496594Z 0 [ERROR] InnoDB: Your database may be corrupt or you may have copied the InnoDB tablespace but not the InnoDB log files. Please refer to http://dev.mysql.com/doc/refman/5.7/en/forcing-innodb-recovery.html for information about forcing recovery. 2025-10-24T06:14:53.499300Z 0 [ERROR] InnoDB: Page [page id: space=488, page number=3] log sequence number 1818075769646 is in the future! Current system log sequence number 1818072347793. 2025-10-24T06:14:53.500195Z 0 [ERROR] InnoDB: Page [page id: space=26, page number=22] log sequence number 1818074006086 is in the future! Current system log sequence number 1818072347793. 2025-10-24T06:14:53.503793Z 0 [ERROR] InnoDB: Your database may be corrupt or you may have copied the InnoDB tablespace but not the InnoDB log files. Please refer to http://dev.mysql.com/doc/refman/5.7/en/forcing-innodb-recovery.html for information about forcing recovery. 2025-10-24T06:14:53.505862Z 0 [ERROR] InnoDB: Your database may be corrupt or you may have copied the InnoDB tablespace but not the InnoDB log files. Please refer to http://dev.mysql.com/doc/refman/5.7/en/forcing-innodb-recovery.html for information about forcing recovery. 2025-10-24T06:14:53.513791Z 0 [ERROR] InnoDB: Page [page id: space=26, page number=23] log sequence number 1818074993296 is in the future! Current system log sequence number 1818072347793. 2025-10-24T06:14:53.515785Z 0 [ERROR] InnoDB: Your database may be corrupt or you may have copied the InnoDB tablespace but not the InnoDB log files. Please refer to http://dev.mysql.com/doc/refman/5.7/en/forcing-innodb-recovery.html for information about forcing recovery. 2025-10-24T06:14:53.524243Z 0 [ERROR] InnoDB: Page [page id: space=488, page number=527] log sequence number 1818080514186 is in the future! Current system log sequence number 1818072347793. 2025-10-24T06:14:53.528019Z 0 [ERROR] InnoDB: Your database may be corrupt or you may have copied the InnoDB tablespace but not the InnoDB log files. Please refer to http://dev.mysql.com/doc/refman/5.7/en/forcing-innodb-recovery.html for information about forcing recovery. 2025-10-24T06:14:53.537996Z 0 [ERROR] InnoDB: Page [page id: space=540, page number=7] log sequence number 1818081166468 is in the future! Current system log sequence number 1818072347793. 2025-10-24T06:14:53.541042Z 0 [ERROR] InnoDB: Your database may be corrupt or you may have copied the InnoDB tablespace but not the InnoDB log files. Please refer to http://dev.mysql.com/doc/refman/5.7/en/forcing-innodb-recovery.html for information about forcing recovery. 2025-10-24T06:14:53.543656Z 0 [ERROR] InnoDB: Page [page id: space=26, page number=31] log sequence number 1818075024348 is in the future! Current system log sequence number 1818072347793. 2025-10-24T06:14:53.548712Z 0 [ERROR] InnoDB: Your database may be corrupt or you may have copied the InnoDB tablespace but not the InnoDB log files. Please refer to http://dev.mysql.com/doc/refman/5.7/en/forcing-innodb-recovery.html for information about forcing recovery. 2025-10-24T06:14:53.554624Z 0 [ERROR] InnoDB: Page [page id: space=540, page number=4] log sequence number 1818081150547 is in the future! Current system log sequence number 1818072347793. 2025-10-24T06:14:53.558427Z 0 [ERROR] InnoDB: Your database may be corrupt or you may have copied the InnoDB tablespace but not the InnoDB log files. Please refer to http://dev.mysql.com/doc/refman/5.7/en/forcing-innodb-recovery.html for information about forcing recovery. 2025-10-24T06:14:53.565031Z 0 [ERROR] InnoDB: Page [page id: space=539, page number=4] log sequence number 1818080173025 is in the future! Current system log sequence number 1818072347793. 2025-10-24T06:14:53.567157Z 0 [ERROR] InnoDB: Page [page id: space=26, page number=31683] log sequence number 1818075654250 is in the future! Current system log sequence number 1818072347793. 2025-10-24T06:14:53.567489Z 0 [ERROR] InnoDB: Your database may be corrupt or you may have copied the InnoDB tablespace but not the InnoDB log files. Please refer to http://dev.mysql.com/doc/refman/5.7/en/forcing-innodb-recovery.html for information about forcing recovery. 2025-10-24T06:14:53.571042Z 0 [ERROR] InnoDB: Your database may be corrupt or you may have copied the InnoDB tablespace but not the InnoDB log files. Please refer to http://dev.mysql.com/doc/refman/5.7/en/forcing-innodb-recovery.html for information about forcing recovery. 2025-10-24T06:14:53.598497Z 0 [Note] Found ca.pem, server-cert.pem and server-key.pem in data directory. Trying to enable SSL support using them. 2025-10-24T06:14:53.601463Z 0 [Note] Skipping generation of SSL certificates as certificate files are present in data directory. 2025-10-24T06:14:53.603981Z 0 [Warning] A deprecated TLS version TLSv1 is enabled. Please use TLSv1.2 or higher. 2025-10-24T06:14:53.605450Z 0 [ERROR] InnoDB: Page [page id: space=743, page number=0] log sequence number 1818074641633 is in the future! Current system log sequence number 1818072347793. 2025-10-24T06:14:53.606048Z 0 [Warning] A deprecated TLS version TLSv1.1 is enabled. Please use TLSv1.2 or higher. 2025-10-24T06:14:53.609638Z 0 [ERROR] InnoDB: Your database may be corrupt or you may have copied the InnoDB tablespace but not the InnoDB log files. Please refer to http://dev.mysql.com/doc/refman/5.7/en/forcing-innodb-recovery.html for information about forcing recovery. InnoDB: Dump of the tablespace extent descriptor: len 40; hex 0000000000000000ffffffff0000ffffffff000000000002aaffffffffffffffffffffffffffffff; asc ;2025-10-24T06:14:53.618233Z 0 [ERROR] InnoDB: InnoDB is trying to free page [page id: space=743, page number=8] though it is already marked as free in the tablespace! The tablespace free space info is corrupt. You may need to dump your tables and recreate the whole database! 2025-10-24T06:14:53.622034Z 0 [ERROR] [FATAL] InnoDB: Please refer to http://dev.mysql.com/doc/refman/5.7/en/forcing-innodb-recovery.html for information about forcing recovery. 2025-10-24T06:14:53.624235Z 0 [Warning] CA certificate ca.pem is self signed. 2025-10-24 14:14:53 0x354c InnoDB: Assertion failure in thread 13644 in file ut0ut.cc line 921 InnoDB: We intentionally generate a memory trap. InnoDB: Submit a detailed bug report to http://bugs.mysql.com. InnoDB: If you get repeated assertion failures or crashes, even InnoDB: immediately after the mysqld startup, there may be InnoDB: corruption in the InnoDB tablespace. Please refer to InnoDB: http://dev.mysql.com/doc/refman/5.7/en/forcing-innodb-recovery.html InnoDB: about forcing recovery. 2025-10-24T06:14:53.625645Z 0 [Note] Skipping generation of RSA key pair as key files are present in data directory. 2025-10-24T06:14:53.628676Z 0 [Note] Server hostname (bind-address): '*'; port: 3308 2025-10-24T06:14:53.629979Z 0 [Note] IPv6 is available. 2025-10-24T06:14:53.630668Z 0 [Note] - '::' resolves to '::'; 2025-10-24T06:14:53.632389Z 0 [Note] Server socket created on IP: '::'. 2025-10-24T06:14:53.747077Z 0 [ERROR] InnoDB: Page [page id: space=26, page number=16384] log sequence number 1818075741603 is in the future! Current system log sequence number 1818072347793. 2025-10-24T06:14:53.751073Z 0 [ERROR] InnoDB: Your database may be corrupt or you may have copied the InnoDB tablespace but not the InnoDB log files. Please refer to http://dev.mysql.com/doc/refman/5.7/en/forcing-innodb-recovery.html for information about forcing recovery. 2025-10-24T06:14:53.924848Z 0 [Note] Failed to start slave threads for channel '' 2025-10-24T06:14:54.002381Z 0 [Note] Event Scheduler: Loaded 0 events 2025-10-24T06:14:54.003266Z 0 [Note] C:\Program Files\MySQL\MySQL Server 5.7\bin\mysqld.exe: ready for connections. Version: '5.7.43-log' socket: '' port: 3308 MySQL Community Server (GPL) 2025-10-24T06:14:54.063857Z 0 [ERROR] InnoDB: Page [page id: space=28, page number=0] log sequence number 1818073721575 is in the future! Current system log sequence number 1818072347793. 2025-10-24T06:14:54.067646Z 0 [ERROR] InnoDB: Your database may be corrupt or you may have copied the InnoDB tablespace but not the InnoDB log files. Please refer to http://dev.mysql.com/doc/refman/5.7/en/forcing-innodb-recovery.html for information about forcing recovery. 2025-10-24T06:14:54.073181Z 0 [ERROR] InnoDB: Page [page id: space=28, page number=4] log sequence number 1818073721575 is in the future! Current system log sequence number 1818072347793. 2025-10-24T06:14:54.076879Z 0 [ERROR] InnoDB: Your database may be corrupt or you may have copied the InnoDB tablespace but not the InnoDB log files. Please refer to http://dev.mysql.com/doc/refman/5.7/en/forcing-innodb-recovery.html for information about forcing recovery. 2025-10-24T06:14:54.081031Z 0 [ERROR] InnoDB: Page [page id: space=28, page number=5] log sequence number 1818073639109 is in the future! Current system log sequence number 1818072347793. 2025-10-24T06:14:54.083439Z 0 [ERROR] InnoDB: Your database may be corrupt or you may have copied the InnoDB tablespace but not the InnoDB log files. Please refer to http://dev.mysql.com/doc/refman/5.7/en/forcing-innodb-recovery.html for information about forcing recovery. 2025-10-24T06:14:54.087366Z 0 [ERROR] InnoDB: Page [page id: space=488, page number=0] log sequence number 1818074963526 is in the future! Current system log sequence number 1818072347793. 2025-10-24T06:14:54.089008Z 0 [ERROR] InnoDB: Your database may be corrupt or you may have copied the InnoDB tablespace but not the InnoDB log files. Please refer to http://dev.mysql.com/doc/refman/5.7/en/forcing-innodb-recovery.html for information about forcing recovery. 2025-10-24T06:14:54.840960Z 0 [Note] InnoDB: Buffer pool(s) load completed at 251024 14:14:54
10-25
| 5 (`SRV_FORCE_NO_UNDO_LOG_SCAN`) | 不扫描 undo 日志 | | 6 (`SRV_FORCE_NO_LOG_REDO`) | 完全跳过日志重做 | --- ### 步骤二：重启 MySQL 服务 ```bash net stop mysql net start mysql ``` 观察错误日志...
oracle数据库脏读,参考oracle官方文档关于脏读、一致性读、undo中已提交数据块的理解...
weixin_33643788的博客
04-03 666
脏读Dirty readsA transaction reads data that has been written by another transaction that has not been committed yet.一个事务读取另一个尚未提交的事务写入的数据。Oracle Database never permits dirty reads, which occur when a t...
数据结构与算法Python实现完整代码库与习题解答项目_包含Python语言入门面向对象编程算法分析递归基于数组的序列栈队列双端队列链表树优先级队列映射哈希表跳跃表搜索树排序选择文.zip
12-20
数据结构与算法Python实现完整代码库与习题解答项目_包含Python语言入门面向对象编程算法分析递归基于数组的序列栈队列双端队列链表树优先级队列映射哈希表跳跃表搜索树排序选择文.zip
练习材料-用word邮件合并功能批量生成缴费单
最新发布
12-20
练习材料-用word邮件合并功能批量生成缴费单
csdn上传文件抓包啊
12-20
csdn上传文件抓包啊
2025年智能物流智能物流系统建设实施方案PDF
12-20
当前，全球经济格局深刻调整，数字化浪潮席卷各行各业，智能物流作为现代物流发展的必然趋势和关键支撑，正迎来前所未有的发展机遇。以人工智能、物联网、大数据、云计算、区块链等前沿信息技术的快速迭代与深度融合为驱动，智能物流不再是传统物流的简单技术叠加，而是正在经历一场从自动化向智能化、从被动响应向主动预测、从信息孤岛向全面互联的深刻变革。展望2025年，智能物流系统将不再局限于提升效率、降低成本的基本目标，而是要构建一个感知更全面、决策更精准、执行更高效、协同更顺畅的智慧运行体系。这要求我们必须超越传统思维定式，以系统化、前瞻性的视角，全面规划和实施智能物流系统的建设。本实施方案正是基于对行业发展趋势的深刻洞察和对未来需求的精准把握而制定。我们的核心目标在于:通过构建一个集成了先进感知技术、大数据分析引擎、智能决策算法和高效协同平台的综合智能物流系统，实现物流全链路的可视化、透明化和智能化管理。这不仅是技术层面的革新，更是管理模式和服务能力的全面提升。本方案旨在明确系统建设的战略方向、关键任务、技术路径和实施步骤，确保通过系统化部署，有效应对日益复杂的供应链环境，提升整体物流韧性，优化资源配置效率，降低运营成本，并最终为客户创造更卓越的价值体验。我们致力于通过本方案的实施，引领智能物流迈向更高水平，为构建现代化经济体系、推动高质量发展提供强有力的物流保障。
hls高层次综合设计宝藏
12-20
hls设计你不会，那是你对底层设计不懂，来不，看下hls蓝宝书，你就会了。
iTop Easy Desktop v4.0.0.230.exe
12-20
iTop Easy Desktop v4.0.0.230.exe
oracle CREATE UNDO TABLESPACE
10-22
### 类型 在 Oracle 中，`CREATE UNDO TABLESPACE` 用于创建撤销表空间，它是一种特殊类型的表空间。撤销表空间主要用于存储事务修改数据之前的旧值，属于系统级别的存储结构，与用户数据、索引等存储在不同的表空间中。 ### 用途 - **事务回滚**：当事务执行 `ROLLBACK` 语句时，Oracle 可以利用撤销表空间中的旧数据将数据恢复到事务开始之前的状态。 - **读一致性**：保证用户在查询数据时，即使有其他事务正在修改这些数据，查询结果仍然是事务开始时的数据状态，避免了脏读等问题。 - **闪回查询**：支持用户查询过去某个时间点的数据，通过撤销表空间中的旧数据来实现。 ### 使用方法 创建撤销表空间的基本语法如下： ```sql CREATE UNDO TABLESPACE tablespace_name DATAFILE 'file_name' [ SIZE size_clause ] [ AUTOEXTEND [ON | OFF] [ NEXT next_clause ] [ MAXSIZE maxsize_clause ] ] [ EXTENT MANAGEMENT LOCAL [ UNIFORM SIZE size_clause ] ] [ SEGMENT SPACE MANAGEMENT { AUTO | MANUAL } ]; ``` 参数说明： - `tablespace_name`：撤销表空间的名称。 - `file_name`：指定撤销表空间的数据文件路径和名称。 - `SIZE size_clause`：指定数据文件的初始大小，例如 `SIZE 100M` 表示初始大小为 100MB。 - `AUTOEXTEND`：指定数据文件是否自动扩展，`ON` 表示自动扩展，`OFF` 表示不自动扩展。 - `NEXT next_clause`：当数据文件需要扩展时，每次扩展的大小。 - `MAXSIZE maxsize_clause`：数据文件允许扩展到的最大大小。 - `EXTENT MANAGEMENT LOCAL`：指定表空间采用本地管理方式，这是推荐的管理方式。 - `UNIFORM SIZE size_clause`：指定统一的区大小。 - `SEGMENT SPACE MANAGEMENT`：指定段空间管理方式，`AUTO` 表示自动管理，`MANUAL` 表示手动管理。 示例： ```sql CREATE UNDO TABLESPACE undotbs_02 DATAFILE '/u01/oracle/rbdb1/undotbs_02.dbf' SIZE 200M AUTOEXTEND ON NEXT 50M MAXSIZE 500M EXTENT MANAGEMENT LOCAL UNIFORM SIZE 1M SEGMENT SPACE MANAGEMENT AUTO; ```
评论
添加红包

请填写红包祝福语或标题

个

红包个数最小为10个

元

红包金额最低5元

当前余额3.43元 前往充值 >
需支付：10.00元
成就一亿技术人!
领取后你会自动成为博主和红包主的粉丝 规则
hope_wisdom
发出的红包
实付元
使用余额支付
点击重新获取
扫码支付
钱包余额 0

抵扣说明：

1.余额是钱包充值的虚拟货币，按照1:1的比例进行支付金额的抵扣。
2.余额无法直接购买下载，可以购买VIP、付费专栏及课程。

余额充值