The talk from here. 1. The lifecycle in Angular component: constructor vs ngOnInit: Constructor: only used for injection. ngOnInit: for data initlization. About ngOnInit:  I am not sure the example is good or not. Because it is not a good choice to u…

Performance Tips 1.In this document Avoid Creating Unnecessary Objects 避免多余的对象 Prefer Static Over Virtual  多用static方法,它比其它方法快15%-20% Use Static Final For Constants   多用 static final 基本类型常量 Avoid Internal Getters/Setters   在类内部避免使用getter,setter而直接使用成员…

Refer to: http://harriyott.com/2006/01/sql-server-performance-tips A colleague of mine has been looking at SQL Server performance, and come up with a great set of tips (mostly gleaned from this website): Does your SQL statement have a WHERE clause? I…

HTML5 Techniques for Optimizing Mobile Performance Scrolling Performance layout-performance…

原文: http://www.newtonsoft.com/json/help/html/Performance.htm To keep an application consistently fast, it is important to minimize the amount of time the .NET framework spends performing garbage collection. Allocating too many objects or allocating v…

For example you make a function to get rating; getRating(score: number): string { let rating: string; console.count('RatingPipe'); if(score > 249000){ rating = "Daniel Boone"; } else if(score > 200000){ rating = "Trail Guide"; }…

1.避免使用同步代码: // Good: write files asynchronously fs.writeFile('message.txt', 'Hello Node', function (err) { console.log("It's saved and the server remains responsive!"); }); // BAD: write files synchronously fs.writeFileSync('message.txt', 'Hello…

/** Let inheritance help with memory efficiency */ function SignalFire(ID, startingLogs){ this.fireID = ID; this.logsLeft = startingLogs; } SignalFire.prototype = { addLogs: function(numLogs){ this.logsLeft += numLogs; } lightFire: function(){ alert(…

本文由CocoaChina译者yake_099(博客)翻译,作者:David McGraw原文:10 Actionable Performance Tips To Speed Up Your Table View 在我们开始之前,我准备从今年开始多听取一个意见.请花一些时间通过这篇简短的调查给我们一些反馈.这将会帮助我来帮助你. 如果你曾经跟collectionview打过交道,你可能已经意识到了这篇文章的价值.如果你没有注意速度这将会是一个大问题,你的用户会让你了解的.当你的scrollvie…

1 compress & mr hive默认的execution engine是mr hive> set hive.execution.engine;hive.execution.engine=mr 所以针对mr的优化就是hive的优化,比如压缩和临时目录 mapred-site.xml <property> <name>mapreduce.map.output.compress</name> <value>true</value>…