大约有 48,000 项符合查询结果（耗时：0.0830秒） [XML]
What does ON [PRIMARY] mean?
I'm creating an SQL setup script and I'm using someone else's script as an example. Here's an example of the script:
4 Ans...
MYSQL OR vs IN performance
... not believe people who give their "opinion", science is all about testing and evidence.
I ran a loop of 1000x the equivalent queries (for consistency, I used sql_no_cache):
IN: 2.34969592094s
OR: 5.83781504631s
Update:
(I don't have the source code for the original test, as it was 6 years ago, ...
External VS2013 build error “error MSB4019: The imported project was not found”
I am building a project through the command line and not inside Visual Studio 2013. Note, I had upgraded my project from Visual Studio 2012 to 2013. The project builds fine inside the IDE. Also, I completely uninstalled VS2012 first, rebooted, and installed VS2013. The only version of Visual Studio ...
HTML5 Local storage vs. Session storage
Apart from being non persistent and scoped only to the current window, are there any benefits (performance, data access, etc) to Session Storage over Local Storage?
...
master branch and 'origin/master' have diverged, how to 'undiverge' branches'?
Somehow my master and my origin/master branch have diverged.
I actually don't want them to diverge.
13 Answers
...
What's the difference between “STL” and “C++ Standard Library”?
... (I'm paraphrasing) the STL term is misused to refer to the entire C++ Standard Library instead of the parts that were taken from SGI STL.
...
Error-Handling in Swift-Language
... thing I noticed is that there are no exceptions.
So how do they do error handling in Swift? Has anyone found anything related to error-handling?
...
Java 8: performance of Streams vs Collections
... the middle of the list using iterator.
Stop writing benchmarking code by hand, use JMH.
Proper benchmarks:
@OutputTimeUnit(TimeUnit.NANOSECONDS)
@BenchmarkMode(Mode.AverageTime)
@OperationsPerInvocation(StreamVsVanilla.N)
public class StreamVsVanilla {
public static final int N = 10000;
...
Efficient way to return a std::vector in c++
How much data is copied, when returning a std::vector in a function and how big an optimization will it be to place the std::vector in free-store (on the heap) and return a pointer instead i.e. is:
...
Is there any significant difference between using if/else and switch-case in C#?
... (unlike many other languages) also allows to switch on string constants - and this works a bit differently. It's obviously not practical to build jump tables for strings of arbitrary lengths, so most often such switch will be compiled into stack of IFs.
But if number of conditions is big enough t...