Community Learn Tools Library Leisure
search
English
Home > Database > Mysql Tutorial > undo系列学习之undo段及区的状态和使用概述

undo系列学习之undo段及区的状态和使用概述

WBOY
Release： 2016-06-07 17:17:46
Original
1350 people have browsed it

undo表空间只做一件事：保存旧值。在AUM下，段是自动生成，区是自动分配与回收，且是不连续的。oracle自动使用undo段，在某种意义

undo表空间只做一件事：保存旧值。在AUM下，段是自动生成，区是自动分配与回收，且是不连续的。Oracle自动使用undo段，，在某种意义上，我们只要关注undo表空间的大小就可以了。

查询当前哪个undo表空间被激活：

查询undo表空间里面有多少个数据文件：

查询undo表空间里面在线有多少个段：

查询段有多少个区和块：

查询区有多少个块：

从这里我们也可以看出，undo段中的区的分配是不连续的。

linux

Related labels：
undo
source：php.cn
Previous article：RHEL5开启和关闭Oracle实例以及自启动 Next article：图解MySQL学习及思考
Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
Latest Articles by Author
Latest Issues
function_exists() cannot determine the custom function Function test () {return true;} if (function_exists ('test')) {echo "test is function...
From 2024-04-29 11:01:01
0
3
2205
How to display the mobile version of Google Chrome Hello teacher, how can I change Google Chrome into a mobile version?
From 2024-04-23 00:22:19
0
11
2354
The child window operates the parent window, but the output does not respond. The first two sentences are executable, but the last sentence cannot be implemented.
From 2024-04-19 15:37:47
0
1
1971
There is no output in the parent window document.onclick = function(){ window.opener.document.write('I am the output of the child ...
From 2024-04-18 23:52:34
0
1
1857
Where is the courseware about CSS mind mapping? Courseware
From 2024-04-16 10:10:18
0
0
1921
Related Topics
More>
Popular Recommendations
Popular Tutorials
More>
Related Tutorials
Popular Recommendations
Latest courses
Latest Downloads
More>
Web Effects
Website Source Code
Website Materials
Front End Template