2008-06-05
全文显示

mysql query cache

关键字: mysql query cache transaction
1. works with Transactions http://www.mysqlperformanceblog.com/2008/01/29/how-mysql-query-cache-works-with-transactions/ 写道 The result set can be retrieved from query cache (for statements both inside and outside of transactions) until there is a statement inside transactions which modifie ...
2008-05-26
全文显示

javascript object model

关键字: javascript object function
the difference between prototype property and [[prototype]] which constructs the chain of prorotype each object has a inner property called '[[prototype]] ', whose value is null or point to some object. This property is visible only for JS engine.(in firefox, this property can visited ...
2008-05-23
全文显示

some thoughts of composite & visitor pattern

关键字: composite command visitor java pattern
At first, let's look the typical class structure diagram of composite pattern:   Composite pattern is very suitable for Tree structure. The picture showed above defines a Interface Node and two sub concrete tree types  : Leaf  and Branch.  Branch may contains sub branch and ...
2008-05-22
全文显示

best practices for web form design

关键字: ui web form
These contents are refered from a pdf file named 'best practices for web form design '. information Layout top aligned : for reduced completion times & familiar data input. right aligned : when vertical screen space is a constraint. left aligned : for unfamiliar, or advanced ...
2008-05-21
全文显示

InnoDB transaction model

关键字: transaction mysql innodb
At first, lst's understand some technologies used in mysql transaction model: 1. Next-Key Locking http://dev.mysql.com/doc/refman/5.0/en/innodb-next-key-locking.html 写道 InnoDB performs the row-level locking in such a way that when it searches or scans an index of a table, it sets shared or ex ...
2008-05-20
全文显示

JSP directives & standard actions

关键字: jsp
Three jsp directives 1. the page directive first, refere the explaination of it in jsp specificiation: the page directive defines a number of page dependent properties and communicates these to the JSP container.  this directive is so common that always can  be see in the top o ...
2008-05-19
全文显示

implement url-rewrite in j2ee application

关键字: urlrewritefilter j2ee
in many j2ee applications, especially which developed by light-weight framework,such as struts, we can easily see the url pattern as  follows : 写道 http://localhost:8080/app/module/action.do?id=x&  In contrast, the url pattern used by ruby on rails applications are totally different: ...
2008-03-11
全文显示

用criteria进行关联查询

关键字: criteria
问题描述如下： 引用两个实体 Parent(P) 和 Child(C)之间是1：N的关系，现要求符合指定条件的P及所包 含的C 采用hibernate中的Criteria来实现此功能的代码如下： Criteria criteria = this.getCriteria(Parent.class); //连接关联子对象child，且指定了连接方式为左外连接 criteria.createAlias("children", "c", CriteriaSpecification.LEFT_JOIN)); //下面三行代码是用于获取总的记录数 criteria.setProjection ...
2007-11-09
全文显示

java序列化机制学习

关键字: 序列化 serializable externalizable
什么是序列化 java中的序列化(serialization)机制能够将一个实例对象的状态信息写入到一个字节流中，使其可以通过socket进行传输、或者持久化存储到数据库或文件系统中；然后在需要的时候，可以根据字节流中的信息来重构一个相同的对象。序列化机制在java中有着广泛的应用，EJB、RMI等技术都是以此为基础的。 正确使用序列化机制 一般而言，要使得一个类可以序列化，只需简单实现java.io.Serializable接口即可。该接口是一个标记式接口，它本身不包含任何内容，实现了该接口则表示这个类准备支持序列化的功能。如下例定义了类Person，并声明其可以序列化。 publi ...
2007-10-30
全文显示

oracle中的索引及其使用

Oracle 中有两种主要的索引机制：B-树索引(B-tree indexes) 和 位图索引(bitmap indexes)，其它的一些索引，如位图连接索引(bitmap join index)、基于函数的索引(function-based indexes)、反转键索引(reverse key indexes)等，都是基于这两种索引的变体。本文主要介绍这两种主要的索引机制。 一 基础知识 1. 数据块(data bolck)     数据块是Oracle中管理数据文件中存储空间的单位，是数据库使用的I/O的最小单位。Oracle中所有的逻辑数据库结构，如表 ...