ICQMX.NET

Yesterday, I wrote three very simple programs in different programming languages including C++, C# and Java. These programs will use trial division method to find 200000 prime numbers that is starting from 2 orderly. Then, the found prime numbers will store in an array. I found that C++ has the best performance, and the next are Java and C#. However, you don’t need to take the test seriously. I know this test can’t represent the whole performance of C++, C# and Java. And it ‘s just for fun.

Compilers:

C++
MS 32-bit C/C++ Optimizing Compiler Version 15.00.30729.01 for 80×86 and
MS Incremental Linker Version 9.00.30729.01
compilation command: cl /EHsc /Ox primeN.cpp

C#
MS Visual C# 2008 Compiler version 3.5.30729.1 (.NET Framework 3.5)
compilation command: csc primeN.cs

Java
Java SE Development Kit 6 Update 11
compilation command: javac primeN.java

Environments:

OS: Windows Vista Business SP1 (32bit)
CPU: AMD Athlon 64 x2 5400+
RAM: 4GB

Result:

Download the source codes

WordPress 2.7 build-in revision feature to save all backup articles (or you may call posts). However, the backup articles almost will not be used and a lot of database storage is wasted. Therefore, I disabled revision feature in my blog. Here is the solution to turn this feature off.

1. Edit wp-config.php that is saved in WordPress root directory.
2. Add the following red statement at wp-config.php. It’s suggested to add the red statement at the last 2 line (before ?>).
   ...........
require_once(ABSPATH . 'wp-settings.php');
define('WP_POST_REVISIONS', false);
?>


If you have wrote many articles previously, I believe your database has already stored many unnecessary articles. To release the storage, it is suggested to remove the existing revision articles.

1. Go to phpMyAdmin
2. Click SQL button:
   
3. Enter and submit the following SQL statements:
   DELETE FROM wp_posts WHERE post_type = "revision";
4. Finally, phpMyAdmin will show you how many revision articles have been deleted:
   
5. If error occurs, you should substitute wp_ to the table prefix of your WordPress