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What is the real overhead of try/catch in C#?
... to make here:
Firstly, there is little or NO performance penalty in actually having try-catch blocks in your code. This should not be a consideration when trying to avoid having them in your application. The performance hit only comes into play when an exception is thrown.
When an exception is th...
JOIN queries vs multiple queries
...ase. It depends on a lot of things. Jeff Atwood (founder of this site) actually wrote about this. For the most part, though, if you have the right indexes and you properly do your JOINs it is usually going to be faster to do 1 trip than several.
...
Why would I use a templating engine? jsp include and jstl vs tiles, freemarker, velocity, sitemesh
...scope, by controllers) to fill these placeholders.
Yes, references are really the core of VTL:
<b>Hello $username!</b>
or
#if($listFromModel.size() > 1)
You have many entries!
#end
Efficiency - <%@ include file="file.jsp" %> is more efficient than anything else, b...
Amazon SimpleDB vs Amazon DynamoDB
...:
While SimpleDB has scaling limitations, it may be a good fit for
smaller workloads that require query flexibility. Amazon SimpleDB
automatically indexes all item attributes and thus supports query
flexibility at the cost of performance and scale.
So it's a trade off between performance...
Selecting multiple columns in a pandas dataframe
...).
df1 = df[['a', 'b']]
Alternatively, if it matters to index them numerically and not by their name (say your code should automatically do this without knowing the names of the first two columns) then you can do this instead:
df1 = df.iloc[:, 0:2] # Remember that Python does not slice inclusive of...
Is it possible to specify your own distance function using scikit-learn K-Means Clustering?
...
Here's a small kmeans that uses any of the 20-odd distances in
scipy.spatial.distance, or a user function.
Comments would be welcome (this has had only one user so far, not enough);
in particular, what are your N, dim, k, metric ?
#!/u...
Can you force Visual Studio to always run as an Administrator in Windows 8?
...Env\VSLauncher.exe file if you have multiple versions of Visual Studio installed. Also, the default paths to the devenv.exe files is: Visual Studio 2010 - C:\Program Files (x86)\Microsoft Visual Studio 10.0\Common7\IDE\devenv.exe. Visual Studio 2012 - C:\Program Files (x86)\Microsoft Visual Studio 1...
How can I get last characters of a string
...the answer, using slice this way is also more performant: jsperf.com/slice-vs-substr-and-length
– theVinchi
Oct 20 '16 at 15:49
...
When should I use the Visitor Design Pattern? [closed]
...want to make the fewest possible modifications to it.
The Visitor pattern allows you to move each new operation in a suitable class, and you need to extend the hierarchy's interface only once. Let's do it. First, we define an abstract operation (the "Visitor" class in GoF) which has a method for ev...
How to count the frequency of the elements in an unordered list?
...
nice, using groupby. I wonder about its efficiency vs. the dict approach, though
– Eli Bendersky
Jan 29 '10 at 12:20
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