Community Learn Tools Library Leisure
search
English
Home > Database > Mysql Tutorial > Oracle 解释执行计划

Oracle 解释执行计划

WBOY
Release： 2016-06-07 17:26:13
Original
1173 people have browsed it

执行计划展示的时候类似于一个表格形式，其实它是一个树形结构。该树形结构不仅阐述了SQL引擎执行操作的顺序，也阐明了它们之间的

一. 执行计划树形结构

执行计划展示的时候类似于一个表格形式，其实它是一个树形结构。该树形结构不仅阐述了SQL引擎执行操作的顺序，也阐明了它们之间的关系。树上的每一个节点都代表一个操作，比如表访问，连接，，排序等。各操作之间存在父子关系，具体规则如下：

1. 父有一个或多个子

2. 子只有一个父

3. 唯一没有父的是根节点

4. 执行计划显示的时候，子缩进到父的右侧

5. 父在他孩子前面（父ID小于孩子的ID）

如下图所示：

对应树形结构

下面我们将分类解释各种执行计划

linux

Related labels：
Oracle解释计划 Oracle执行计划 Oracle 解
source：php.cn
Previous article：Linux下Oracle 10g手工建库全过程 Next article：Oracle中位运算函数试验
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
2193
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
2340
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
1963
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
1851
Where is the courseware about CSS mind mapping? Courseware
From 2024-04-16 10:10:18
0
0
1910
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