大约有 42,000 项符合查询结果（耗时：0.0310秒） [XML]
select * vs select column
If I just need 2/3 columns and I query SELECT * instead of providing those columns in select query, is there any performance degradation regarding more/less I/O or memory?
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第一个Hello,OS World操作系统 - 操作系统(内核) - 清泛网 - 专注C/C++及内核技术
第一个Hello,OS World操作系统hello_os_word_my_first_os操作系统并非我们想象中的深不可测、遥不可及，只要你对它感兴趣并随我一起动手实践，你也能开发出属于自己的os。本文通过一个最简单的os，完成Hello, OS World文字的输出来演示os...
What is the difference between the operating system and the kernel? [closed]
I do not understand the difference between operating system and kernel. Can someone please explain it?
3 Answers
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Non-alphanumeric list order from os.listdir()
...y containing the following subdirectories: run01, run02, ... run19, run20, and then I generate a list from the following command:
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Linux/Unix command to determine if process is running?
I need a platform independent (Linux/Unix|OSX) shell/bash command that will determine if a specific process is running. e.g. mysqld , httpd ...
What is the simplest way/command to do this?
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CPU Privilege Rings: Why rings 1 and 2 aren't used?
...the modern protection model) only has a concept of privileged (ring 0,1,2) and unprivileged, the benefit to rings 1 and 2 were diminished greatly.
The intent by Intel in having rings 1 and 2 is for the OS to put device drivers at that level, so they are privileged, but somewhat separated from the r...
Using getopts to process long and short command line options
I wish to have long and short forms of command line options invoked using my shell script.
32 Answers
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An error occurred while installing pg (0.17.1), and Bundler cannot continue
I just installed Rails 4.0.2 and when creating a new app, in the bundle stage I get:
16 Answers
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How can I extract embedded fonts from a PDF as valid font files?
...f the pdftk.exe utility that can indicate which fonts are used by a PDF, and wether they are embedded or not.
8 Answers
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Compiling simple Hello World program on OS X via command line
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@mathepic: and the +1. It is not required in C++. If main reaches the end of the function without hitting a return then it implicitly returns 0.
– Martin York
Nov 1 '10 at 22:43
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