﻿<?xml version="1.0" encoding="utf-8" standalone="yes"?><rss version="2.0" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:trackback="http://madskills.com/public/xml/rss/module/trackback/" xmlns:wfw="http://wellformedweb.org/CommentAPI/" xmlns:slash="http://purl.org/rss/1.0/modules/slash/"><channel><title>BlogJava-xwgong-文章分类-sql</title><link>http://www.blogjava.net/g710246442/category/54444.html</link><description>向javaEE前进</description><language>zh-cn</language><lastBuildDate>Wed, 23 Jul 2014 14:44:49 GMT</lastBuildDate><pubDate>Wed, 23 Jul 2014 14:44:49 GMT</pubDate><ttl>60</ttl><item><title>mysql,sql server,oracle的执行计划</title><link>http://www.blogjava.net/g710246442/articles/416082.html</link><dc:creator>龚小伟</dc:creator><author>龚小伟</author><pubDate>Tue, 22 Jul 2014 06:20:00 GMT</pubDate><guid>http://www.blogjava.net/g710246442/articles/416082.html</guid><wfw:comment>http://www.blogjava.net/g710246442/comments/416082.html</wfw:comment><comments>http://www.blogjava.net/g710246442/articles/416082.html#Feedback</comments><slash:comments>0</slash:comments><wfw:commentRss>http://www.blogjava.net/g710246442/comments/commentRss/416082.html</wfw:commentRss><trackback:ping>http://www.blogjava.net/g710246442/services/trackbacks/416082.html</trackback:ping><description><![CDATA[为了优化sql，提高sql的执行效率，很多时候需要用到执行计划，下面简单的说一下三个主流数据库都如何执行查询计划。<br />&nbsp;&nbsp;&nbsp;&nbsp;mysql<br />&nbsp; &nbsp; 通过关键词explain 来显示查询计划。例如：explain select * from table<br />&nbsp; &nbsp; oracle &nbsp;&nbsp;<br />&nbsp; &nbsp; 通过关键词explain plan for来显示查询计划。例如：explain plan for&nbsp;select * from table<br />&nbsp; &nbsp; sql server<br />&nbsp; &nbsp; sql server工具sqlserver management studio 提供的有查询计划功能。点击菜单栏的查询，然后选择"显示估计的执行计划"即可。<br /><img src ="http://www.blogjava.net/g710246442/aggbug/416082.html" width = "1" height = "1" /><br><br><div align=right><a style="text-decoration:none;" href="http://www.blogjava.net/g710246442/" target="_blank">龚小伟</a> 2014-07-22 14:20 <a href="http://www.blogjava.net/g710246442/articles/416082.html#Feedback" target="_blank" style="text-decoration:none;">发表评论</a></div>]]></description></item></channel></rss>