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Oracle进程架构
Oracle的体系结构 进程架构： 1. Database Writer Process(DBWn): Writes modified(dirty) buffers in the...
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Systematic index design consists of two processes
1. Detect SELECT statements that are too slow due to inadequate indexing Worst input: Variable values leading to the longest elapsed time2. Design indexes that make all SELEC...
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HashMap的get方法有可能导致死循环
http://www.baidu.com/s?wd=HashMap%20Infinite%20Loop&pn=10&tn=baiduhome_pg&ie=utf-8&rsv_page=1
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警惕SQL中间的NULL
select * from dual where null like '%*%'no record found.在做一个数据处理的应用的时候，因为忽略了这个，导致数据被多多处理了。一下是出问题的SQL: update CR_VIP_BKG_VIEW_LOAD d ...
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Relational Database Index Design and the Optimizers
1. Focus on the maor issues It is vital to focus on the few really major issues,not on the relatively unimportant detail under which many people drown. This iskey—to foc...
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分析函数中的KEEP
keep可以理解为MIN, MAX的扩展。如果你在GROUP BY的结果里，需要的不是最小、最大值，而是对应最小、最大值的那个行的其他列，就可以用KEEP。比如 MIN(HIRE_DATE) ... GROUP BY DEPARTMENT 这是求每个部门最早的员工...
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Oracle Table Function
Table functions Oracle provides equivalents for the following elements of thisfeature:■ <multiset value constructor by query> is supported usingCAST (MULTISET (<query expression>) AS <nestedtable...
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工作当中碰到的一个UTL_FILE的问题
附件My accountSign outLogged in as chenro4HomeMy pageProjectsKnowledgebaseHelp Search: CS Hosting ServiceOverviewActivityIssuesNew issueGantt...
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UTL_FILE遍历文件
DECLARE v_file_handle utl_file.file_type; v_buffer VARCHAR2(32767);BEGIN v_file_handle := utl_file.fopen('TEST_DIR', 'CR_Create_Jobs.sql', 'r'); dbms_output...
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javascript的面向对象的继承实现
<script> function Rectangle(w, h){ this.width = w; this.height = h; } Rectangle.prototype.area = function(){ return this.width * this.height; }&...
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javascript的superclass继承
<script> function A(a){ this.x = a; } function B(a,b){ alert(a); this.superclass(a); this.y = b; } B.p...
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Star Schema
http://www.orafaq.com/node/2286A Layman's Understanding of Star Schemas.Submitted by Kevin Meade on Sat, 2009-09-26 22:34 WarehousingStar Schemas are proliferating with warehouses these days....
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Oracle Model Clause
SELECT country,prod, YEAR,sales FROM sales_view WHERE country IN ('Italy','Japan')MODEL RETURN UPDATED ROWS PARTITION BY (country)DIMENSION BY (prod, YEAR)MEASURES (sale sales)RULES( sales['Bounc...
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Javascript window.open
最近项目当中遇到了一个javascript浏览器的兼容问题使用window.open打开新的窗口。以下是代码： function openMenuUrl(url, windowId){ if(windowId){ windowId = windowId ...
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Web应用程序优化
http://developer.yahoo.com/performance/rules.htmlBest Practices for Speeding Up Your Web SiteThe Exceptional Performance team has identified a number of best practices for making web pages fast. The...
