大约有 36,000 项符合查询结果（耗时：0.0453秒） [XML]
Why use the INCLUDE clause when creating an index?
...mns while already updating the index. The overhead is the extra memory and CPU used to store redundant info on the index.
If the columns you consider to add as included-columns are often updated (without the index-key-columns being updated) - or - if it is so many of them that the index becomes clo...
Running a cron every 30 seconds
... schedule the next run to coincide with other events, it needs to wake the CPU less often. The 1ms in the example above is not ideal - I usually set accuracy to 1 (1 second) in my sub-minute scheduled jobs, but that would mean that if you look at the log showing the "Hello World" messages, you'd see...
多媒体组件 · App Inventor 2 中文网
...全就是杂乱的，不知是不是因为版本过旧，还是其他设置问题，经过一系列尝试（包括设置文本朗读器的国家及语言属性）仍然是不行的。最终只得选择“Google文字转语言引擎”（语音设置为”中文“），中文朗读的效果也非常...
Is System.nanoTime() completely useless?
..., on x86 systems, Java's System.nanoTime() returns the time value using a CPU specific counter. Now consider the following case I use to measure time of a call:
...
Is it possible to “decompile” a Windows .exe? Or at least view the Assembly?
...roach. Variable names are non-existent; such a thing doesn't exist to your CPU. Library calls are confusing as hell and often require disassembling further binaries. And assembly is hard as hell to read in the best of conditions.
Most professional programmers can't sit and read assembly language wi...
Why doesn't .NET/C# optimize for tail-call recursion?
...what I know.
Sometimes tailcall is a performance win-win. It can save CPU. jmp is
cheaper than call/ret It can save stack. Touching less stack makes for
better locality.
Sometimes tailcall is a performance loss, stack win.
The CLR has a complex mechanism in which to pass more paramet...
Generate random numbers using C++11 random library
...gy doesn't work here because std::vector is actually a good default due to CPU caching. It even outperforms std::list for insertion in the middle. That's true even if you do understand all the containers and could make an informed decision based on algorithmic complexity.
– voi...
What's the difference between size_t and int in C++?
... whose Huge memory mode had 20-bit addresses stored in 32 bits on a 16-bit CPU (but which could support the 32-bit instruction set of the 80386); the Motorola 68000 had a 16-bit ALU with 32-bit registers and addresses; there were IBM mainframes with 15-bit, 24-bit or 31-bit addresses. You also stil...
How to check if PHP array is associative or sequential?
...
I think this would avoid a lot of potential cpu time and memory if one would check if isset($arr[0]) is false before extracting all the keys as is it clearly associative if the array is not empty but has no element in 0 position. As "most" real associative arrays have ...
Can I Replace Apache with Node.js?
...than when data is copied through "user land", but it ends up utilizing the CPU and RAM less, thus being able to handle larger number of connections than the classic way.
The link: https://gist.github.com/1350901
share
...