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When and why are database joins expensive?
...ucing the cost of joins involving string comparisons. Not only will vastly more fit in cache, there's a lot less disk reading to do.
Moreover, a good optimiser will choose the most restrictive condition and apply it before it performs a join, very effectively leveraging the high selectivity of joi...
Is 161803398 A 'Special' Number? Inside of Math.Random()
... answer is 'Because of Math', but I was hoping someone could give a little more insight at a basic level...
2 Answers
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How can I know if a process is running?
...ways put curly braces, since there's always a chance you might have to add more statements there in the future, in which case the braces will already be there when you need them. But for things like this, if you are 100% sure you only need one statement, it's okay to do and syntactically valid.
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Why main does not return 0 here?
... eax register. See en.wikipedia.org/wiki/X86_calling_conventions#cdecl for more information.
– Sylvain Defresne
Dec 30 '11 at 10:04
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Best practice for storing and protecting private API keys in applications [closed]
...eaningless names, where ever possible. Extracting the keys then takes some more time, for figuring out which string serves which purpose.
Note that setting up ProGuard shouldn't be as difficult as you fear. To begin with, you only need to enable ProGuard, as documented in project.properties. If the...
Can I have multiple :before pseudo-elements for the same element?
...n have both a :before and an :after pseudo-element — it just cannot have more than one of each kind.)
As a result, when you have multiple :before rules matching the same element, they will all cascade and apply to a single :before pseudo-element, as with a normal element. In your example, the end...
Unique combination of all elements from two (or more) vectors
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is someone with more rep than me able to accept this answer?
– Josh
Aug 26 '19 at 20:29
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Adding options to select with javascript
...oth mine and Sime Vidas' answer, run because I thought his looked a little more understandable/intuitive than mine and I wondered how that would translate into implementation. According to Chromium 14/Ubuntu 11.04 mine is somewhat faster, other browsers/platforms are likely to have differing results...
Is it more efficient to copy a vector by reserving and copying, or by creating and swapping? [duplic
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Open document with default OS application in Python, both in Windows and Mac OS
...['open', filename])
In Python 3.5+ you can equivalently use the slightly more complex but also somewhat more versatile
subprocess.run(['open', filename], check=True)
If you need to be compatible all the way back to Python 2.4, you can use subprocess.call() and implement your own error checking:...