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COUNT DISTINCT with CONDITIONS
... only positive values. Zeros or negative values would be evaluated as null and won't be included in count.
One thing to note here is that this can be done by reading the table once. When it seems that you have to read the same table twice or more, it can actually be done by reading once, in most of...
What is the reason not to use select *?
...The essence of the quote of not prematurely optimizing is to go for simple and straightforward code and then use a profiler to point out the hot spots, which you can then optimize to be efficient.
When you use select * you're make it impossible to profile, therefore you're not writing clear & s...
How is Perl's @INC constructed? (aka What are all the ways of affecting where Perl modules are searc
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We will look at how the contents of this array are constructed and can be manipulated to affect where the Perl interpreter will find the module files.
Default @INC
Perl interpreter is compiled with a specific @INC default value. To find out this value, run env -i perl -V command (env ...
How to detect a Christmas Tree? [closed]
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I have an approach which I think is interesting and a bit different from the rest. The main difference in my approach, compared to some of the others, is in how the image segmentation step is performed--I used the DBSCAN clustering algorithm from Python's scikit-learn; it...
How to flatten nested objects with linq expression
...ed Feb 2 '15 at 9:41
Madhukar BhandariMadhukar Bhandari
3977 bronze badges
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What is the difference between the states selected, checked and activated in Android?
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The difference between Checked and Activated is actually quite interesting. Even the Google documentation is apologetic (emphasis below added):
... For example, in a list view with single or multiple selection
enabled, the views in the current selec...
TypeScript: Creating an empty typed container array
... In the vast majority of cases the mentioned downsides would be negligible and readability is the most important factor.
*: Fun fact; at the time of writing the performance difference was 60% in Chrome, while in Firefox there was no measurable performance difference.
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When should you branch?
...ing out the following article, which explains the principles of branching, and when to use them:
Ned Batchelder - Subversion branching quick start
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DateTime.Now vs. DateTime.UtcNow
...nciples of how the two properties work. I know the second one is universal and basically doesn't deal with time zones, but can someone explain in detail how they work and which one should be used in what scenario?
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How to pull request a wiki page on GitHub?
...t isn't open for editing. Then I forked the project, edited it on "my end" and tried to do a pull request. It turns out, the wiki isn't in the project, and there isn't a way to commit changes to it.
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