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When should I use a composite index?
..._C )
will benefit a query that uses those fields for joining, filtering, and sometimes selecting. It will also benefit queries that use left-most subsets of columns in that composite. So the above index will also satisfy queries that need
index( column_A, column_B, column_C )
index( column_A, col...
Evenly space multiple views within a container view
...te 'spacer views' that you have set to match heights equally. Then add top and bottom constraints to the labels (see the screenshot).
More specifically, I have a top constraint on 'Spacer View 1' to superview with a height constraint of lower priority than 1000 and with Height Equals to all of ...
“tag already exists in the remote" error after recreating the git tag
...o get everyone who already has the "wrong" tag to delete their "wrong tag" and replace it with the new "right tag".
Testing in Git 2.10/2.11 shows that retaining the old tag is the default behavior for clients running git fetch, and updating is the default behavior for clients running git fetch --t...
Return a value if no rows are found in Microsoft tSQL
...1) > 0 THEN 1 ELSE 0 END AS [Value]
FROM Sites S
WHERE S.Id = @SiteId and S.Status = 1 AND
(S.WebUserId = @WebUserId OR S.AllowUploads = 1)
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What is the difference between exit(0) and exit(1) in C?
Can anyone tell me? What is the difference between exit(0) and exit(1) in C language?
11 Answers
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What is the “right” way to iterate through an array in Ruby?
...arts, is pretty good on this count. There's no difference between an array and a hash (maybe I'm naive, but this seems obviously right to me), and to iterate through either you just do
...
~x + ~y == ~(x + y) is always false?
...
Assume for the sake of contradiction that there exists some x and some y (mod 2n) such that
~(x+y) == ~x + ~y
By two's complement*, we know that,
-x == ~x + 1
<==> -1 == ~x + x
Noting this result, we have,
~(x+y) == ~x + ~y
<==> ~(x+y) + (x+y) == ~x + ~y...
What's the difference between “mod” and “remainder”?
My friend said that there are differences between "mod" and "remainder".
5 Answers
5
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Convert light frequency to RGB?
...
And the Fourmilab article makes the important point that some colours are not representable in RGB (bright oranges being a good example) because you cannot "make" arbitrary colours of light by adding three primary colours tog...
How to calculate date difference in JavaScript?
... milliseconds to years. You must be aware of bissextile year, of timezone, and some days have 23 or 25 hours. Some years have 365,25 days, so there is no simple arithmetic here (still looking for an accurate solution).
– Alexandre Salomé
May 20 '14 at 12:50
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