﻿<?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-rihongedu-随笔分类-oracle资料</title><link>http://www.blogjava.net/rihongedu/category/38896.html</link><description /><language>zh-cn</language><lastBuildDate>Wed, 08 Apr 2009 07:21:37 GMT</lastBuildDate><pubDate>Wed, 08 Apr 2009 07:21:37 GMT</pubDate><ttl>60</ttl><item><title>SQL 优化</title><link>http://www.blogjava.net/rihongedu/archive/2009/04/08/264450.html</link><dc:creator>大驴</dc:creator><author>大驴</author><pubDate>Wed, 08 Apr 2009 06:35:00 GMT</pubDate><guid>http://www.blogjava.net/rihongedu/archive/2009/04/08/264450.html</guid><wfw:comment>http://www.blogjava.net/rihongedu/comments/264450.html</wfw:comment><comments>http://www.blogjava.net/rihongedu/archive/2009/04/08/264450.html#Feedback</comments><slash:comments>0</slash:comments><wfw:commentRss>http://www.blogjava.net/rihongedu/comments/commentRss/264450.html</wfw:commentRss><trackback:ping>http://www.blogjava.net/rihongedu/services/trackbacks/264450.html</trackback:ping><description><![CDATA[&nbsp;&nbsp;&nbsp;&nbsp; 摘要: （1）选择最有效率的表名顺序(只在基于规则的优化器中有效)：&nbsp; Oracle的解析器按照从右到左的顺序处理FROM子句中的表名，FROM子句中写在最后的表(基础表 driving table)将被最先处理，在FROM子句中包含多个表的情况下,你必须选择记录条数最少的表作为基础表。如果有3个以上的表连接查询, 那就需要选择交叉表(intersection table)作为基础表, 交叉...&nbsp;&nbsp;<a href='http://www.blogjava.net/rihongedu/archive/2009/04/08/264450.html'>阅读全文</a><img src ="http://www.blogjava.net/rihongedu/aggbug/264450.html" width = "1" height = "1" /><br><br><div align=right><a style="text-decoration:none;" href="http://www.blogjava.net/rihongedu/" target="_blank">大驴</a> 2009-04-08 14:35 <a href="http://www.blogjava.net/rihongedu/archive/2009/04/08/264450.html#Feedback" target="_blank" style="text-decoration:none;">发表评论</a></div>]]></description></item></channel></rss>