SEARCH KEYWORD -- Data store

  Apple patent shows they are developing "Killer" 3D Camera

This is not the first time that Apple patent shows they have interest on 3D camera technology. In November last year, one Apple patent shows that Apple is developing advanced three-dimensional object recognition and verification technology. According to PatentlyApple report (March 30,2012) one patent released this week shows that Apple is developing a 3D camera technology for the future iOS devices. This 3D camera is described as an advanced component with advanced micro-lens, depth, chrom...

   3D Camera,Apple,Patent     2012-04-03 07:46:35

  Do You Make These 5 Database Design Mistakes?

Look, everyone makes mistakes. It’s true. But not all of us have the chance to make mistakes that end up costing millions of dollars in hardware and production support costs. Any one of the following five mistakes listed below will add additional costs to your company. It’s guaranteed. The costs could be hardware related (extra disk space, network bandwidth), which tend to add up quickly. The costs are also support related (bad performance, database re-design, report cre...

   Database design,Mistake,Advice,Data type,Compatibility     2012-01-03 11:25:13

  How does MySQL handle DROP TABLE

A few days ago, when executing DROP TABLE in MySQL, all processes including DDL and DML were hung until DROP TABLE was completed. I am confused about this phenomenon. I have reviewed the source codes of MySQL to check how MySQL internally handle DROP TABLE. When user trigger DROP TABLE command: ########################MySQL SERVER drop table######################## /* Sql_table.cc  delete (drop) tables. */bool mysql_rm_table( )   /*   Execute the drop of a normal or temporary...

   MySQL,DROP TABLE     2012-09-24 11:34:05

  CASSANDRA data model

Cassandra is an open source distributed database, it combines dynamic key/value and column oriented feature of Bigtable. Features of Cassandra are: Flexible schema, no need to design schema first, it's very convenient to add or delete strings Support range search on keys High usability, extensible. The single node error will not affect the cluster. We can think Cassandra's data model as a 4 or 5 dimensional Hash. COLUMN Columns is the smallest data unit in Cassandra, it is a 3 dimensional data...

   Cassandra,database,sort     2013-06-08 22:07:40

  9 useful jQuery code snippets

jQuery is one of the most popular JS library among front end developers because of its functionality and usability. Here we share with you some useful jQuery code snippets which can be used in our daily front end development. 1. Smoothly return to page top $(document).ready(function() { $("a.topLink").click(function() { $("html, body").animate({ scrollTop: $($(this).attr("href")).offset().top + "px" }, { duration: 500, easing: "swing" ...

   jQuery,Code snippet     2013-07-13 00:11:10

  String.length() vs String.getBytes().length in Java

In Java, String.length() is to return the number of characters in the string, while String.getBytes().length is to return the number of bytes to represent the string with the specified encoding. By default, the encoding will be the value of system property file.encoding, the encoding name can be set manually as well by calling System.setProperty("file.encoding", "XXX"). For example, UTF-8, Cp1252. In many cases, String.length() will return the same value as String.getBytes().length, but in some ...

   Java,UTF8,String,Encoding,Sample     2015-04-01 22:22:23

  Mastering Async/Await in JavaScript: A Comprehensive Guide with Examples

As a veteran JavaScript developer, I have seen the evolution of JavaScript's asynchronous programming landscape. From callbacks to promises and now async/await, JavaScript has come a long way in making it easier to handle asynchronous operations in a clean and readable manner. In this article, we will delve into the world of async/await and explore why it has become a popular choice for handling asynchronous operations in JavaScript. We will cover the basics of async/await, its syntax, and how i...

   JAVASCRIPT,COMPARISON,PROMISE,ASYNC AWAIT     2023-02-12 07:26:15

  Why are column oriented databases so much faster than row oriented databases?

I have been playing around with Hybrid Word Aligned Bitmaps for a few weeks now, and they turn out to be a rather remarkable data structure.  I believe that they are utilized extensively in modern column oriented databases such as Vertica and MonetDB. Essentially HWABs are a data structure that allows you to represent a sparse bitmap (series of 0's and 1's) really efficiently in memory.  The key trick here is the use of run length encoding to compress the bitmap into fe...

   Database,Column oriented,Speed analysis,Vertica     2012-01-29 04:27:05

  Remove duplicated elements in JavaScript array

During interviews, one frequent question asked would be something like how to remove duplicated elements in a JavaScript array and how many different ways you can think of. The interviewee would also be asked to write the code down. In real applications, normally front end would not need to handle this case since normally it would be done by backend, but still it's necessary for front end developers to know different ways of doing this. This post will share some of the common ways to remove dupl...

   JAVASCRIPT,ARRAY,DUPLICATED ELEMENT     2018-09-21 22:32:10

  What are some lesser known but useful Unix commands?

A few that come to mind, some less known, some more: xargs or parallel: run things in parallel, with lots of options sed and awk: more well-known but still super useful for processing text files, and faster than Python or Ruby m4: simple macro processor screen: powerful terminal multiplexing and session persistence yes: print a string a lot cal: nice calendar env: run a command (useful in scripts) look: find English words (or lines in a file) beginning with a string cut and paste and join: data...

   Linux,Unix,Command,Less used     2011-12-27 09:27:49

RECENT