在Java连接Cassandra的情况下, 当使用组合主键时, 默认第一个是Partition Key, 后续的均为Clustering Key. 如果有多个Clustering Key, 在Java中需指定Clustering Key的Order顺序, 否则将出现 "The clustering keys ordering is wrong for @EmbeddedId" 错误. 代码示例: `@Entity(table = "table_name") publ…

1. Cassandra is quicker than postgre and have lower change to lose data. Cassandra doesn't have foreign keys, locking mechanism and etcs, so that it's quicker on writes. 2. Everything in cassandra is a write. Insert/update/delete is also write. 3. Se…

Cassandra之中一共包含下面5种Key: Primary Key Partition Key Composite Key Compound Key Clustering Key 首先,Primary key 是用来获取某一行的数据, 可以是一列或者多列(复合列 composite) Primary = Partition Key  + [Clustering Key] (Clustering Key 可选) Clustering keys 包括下面两种情况: (1) composite k…

简介 最近需要把一个Excel里的issues list全部到JIRA上create 一遍, 总不能手动创建百十来个issues吧, 本文讲述一下如果调用JIRA提供的Rest API 来自动创建issues. 下面是官网的一个例子,用curl 来创建的. Request curl -D- -u fred:fred /rest/api//issue/ Data { "fields": { "project": { "key": "TES…

/*! * jQuery JavaScript Library v3.4.1 * https://jquery.com/ * * Includes Sizzle.js * https://sizzlejs.com/ * * Copyright JS Foundation and other contributors * Released under the MIT license * https://jquery.org/license * * Date: 2019-05-01T21:04Z *…

sizzle是jquery的核心,它用来选择匹配的元素,其代码包含在一个匿名函数中,并以window作为其上下文环境: (function( window, undefined ) { //此处为sizzle代码 })( window ); 匿名函数体内,首先申明了很多变量,比如下边这些正则表达式: classCache = createCache(), /*classCache: function cache( key, value ) { // Use (key + " ") to…

这篇文章主要介绍了JavaScript中创建字典对象(dictionary)实例,本文直接给出了实现的源码,并给出了使用示例,需要的朋友可以参考下 对于JavaScript来说,其自身的Array对象仅仅是个数组,无法提供通过关键字来获取保存的数据,jQuery源码中提供了一种非常好的方式来解决这个问题,先看一下源码: 复制代码代码如下: function createCache() { var keys = []; function cache(key, value) {  // Use (k…

第二步:实现:first,:last,:eq(),even,odd,:gt(),:lt(); :header,:root,:taget; :not(). ;(function( window ){ var arr = []; var push = arr.push; var slice = arr.slice; var select ; var Expr; // 标识 var expando = "sizzle" + 1 * new Date(); // http://www.w3.o…

第二步:实现Sizzle("el,el,el..."),Sizzle("el > el"),Sizzle("el el"),Sizzle("el + el"),Sizzle("el ~ el") (function( window ){ var arr = []; var select ; var Expr; var push = arr.push; // http://www.w3.org/TR/c…

因为国内被墙,看起来不方便,转载下,原文地址:http://android-developers.blogspot.com/2010/07/multithreading-for-performance.html Multithreading For Performance   [This post is by Gilles Debunne, an engineer in the Android group who loves to get multitasked. — Tim Bray] A g…