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How does database indexing work? [closed]
...g on a field that isn’t sorted requires a Linear Search which requires N/2 block accesses (on average), where N is the number of blocks that the table spans. If that field is a non-key field (i.e. doesn’t contain unique entries) then the entire tablespace must be searched at N block accesses.
W...
Does Internet Explorer 8 support HTML 5?
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IE8 beta 2 supports two APIs from HTML5: cross-document messaging and non-SQL storage.
IE8 beta 2 doesn’t implement the HTML5 parsing algorithm or the new elements (no <canvas> or <video> support).
There are also bug f...
rmagick gem install “Can't find Magick-config”
...g to install the rmagick gem. I am on Snowleopard 10.6 using RVM, Ruby 1.9.2-head and Rails 3.05. Responses to similar questions recommended installing ImageMagick, which I successfully did. Other suggested installing the "libmagick9-dev library", however, I can not figure out how to do this.
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How to fix: “HAX is not working and emulator runs in emulation mode”
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200
Yes it should be fixed, HAXM isn't working.
How much RAM is set for use inside your AVD config...
How to run functions in parallel?
...ing'
for i in xrange(10000000): pass
print 'func1: finishing'
def func2():
print 'func2: starting'
for i in xrange(10000000): pass
print 'func2: finishing'
if __name__ == '__main__':
p1 = Process(target=func1)
p1.start()
p2 = Process(target=func2)
p2.start()
p1.join()
p2.join...
How to convert int[] to Integer[] in Java?
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With Java 8, int[] can be converted to Integer[] easily:
int[] data = {1,2,3,4,5,6,7,8,9,10};
// To boxed array
Integer[] what = Arrays.stream( data ).boxed().toArray( Integer[]::new );
Integer[] ever = IntStream.of( data ).boxed().toArray( Integer[]::new );
// To boxed list
List<Integer> ...
Is there a printf converter to print in binary format?
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52 Answers
52
Active
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How do I get an empty array of any size in python?
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241
If by "array" you actually mean a Python list, you can use
a = [0] * 10
or
a = [None] * 10...
Determine the number of NA values in a column
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321
You're over-thinking the problem:
sum(is.na(df$col))
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Should commit messages be written in present or past tense? [closed]
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12 Answers
12
Active
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