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When should I use a composite index?
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You should use a composite index when you are using queries that benefit from it. A composite index that looks like this:
index( column_A, column_B, column_C )
will benefit a query that uses those fields for joining, filtering, and sometimes selecting. It will also benefit quer...
HTML5 Canvas vs. SVG vs. div
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The short answer:
SVG would be easier for you, since selection and moving it around is already built in. SVG objects are DOM objects, so they have "click" handlers, etc.
DIVs are okay but clunky and have awful performance loading at large numbers.
Canvas ha...
When should I use std::thread::detach?
...e flows of execution reaches the destructor.
When a program terminates (ie, main returns) the remaining detached threads executing in the background are not waited upon; instead their execution is suspended and their thread-local objects destructed.
Crucially, this means that the stack of those ...
Which is more efficient, a for-each loop, or an iterator?
Which is the most efficient way to traverse a collection?
7 Answers
7
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How do I remove the passphrase for the SSH key without having to create a new key?
... started a (white)space that command is not recorded to the ~/.bash_hstory Ie. use ` ssh-keygen -p -P oldpassphrase -N "" -f ~/.ssh/id_rsa` and you are fine( unless you have other keylogger there). You could also get rid of the record from the history..
– Huge
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When vectors are allocated, do they use memory on the heap or the stack?
...d from memory, like function return, what will happen to the elements memories? Are them reclaimed with the header info or not? If they are not, will this cause memory leak?
– flyrain
Sep 22 '13 at 17:39
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How to open multiple pull requests on GitHub
...t was only with the master. So what you mean is I can create many branch ( ie: git flow features ) and make pull requests for each of them... Going to try!
– Ziyan Junaideen
Nov 20 '13 at 5:24
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What's the difference between streams and datagrams in network programming?
...ually call the other back since this is an unexpected event; usually the client will reconnect to the server. There is a guarantee that data will not arrive in a different order than you sent it, and there is a reasonable guarantee that data will not be damaged.
A datagram socket is like passing a...
Is the order of iterating through std::map known (and guaranteed by the standard)?
...termine when two keys are the same (by the above rule) and to perform efficient lookup (essentially a binary search, which has logarithmic complexity in the number of elements).
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In C++, what is a “namespace alias”?
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A namespace alias is a convenient way of referring to a long namespace name by a different, shorter name.
As an example, say you wanted to use the numeric vectors from Boost's uBLAS without a using namespace directive. Stating the full namespace every t...