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Counting DISTINCT over multiple columns
... two columns.
Once it is persisted, provided the column is deterministic and you are using "sane" database settings, it can be indexed and / or statistics can be created on it.
I believe a distinct count of the computed column would be equivalent to your query.
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How to checkout in Git by date?
...-27 13:37" master`
Note the --first-parent if you want only your history and not versions brought in by a merge. That's what you usually want.
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Original purpose of ? [closed]
...lude such a description):
type=hidden
These fields should not be rendered and provide a means for servers to store state information with a form. This will be passed back to the server when the form is submitted, using the name/value pair defined by the corresponding attributes. This is a work arou...
SVG Positioning
I'm having a play with SVG and am having a few problems with positioning. I have a series of shapes which are contained in the g group tag. I was hoping to use it like a container, so I could set its x position and then all the elements in that group would also move. But that doesn't seem to be po...
Memory footprint of Haskell data types
...ge conventions)
Rule of thumb: a constructor costs one word for a header, and one word for each field. Exception: a constructor with no fields (like Nothing or True) takes no space, because GHC creates a single instance of these constructors and shares it amongst all uses.
A word is 4 bytes on a ...
Is there a link to GitHub for downloading a file in the latest release of a repository?
...ould redirected to the latest tagged package.zip release asset. Hope it's handy!
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Why doesn't GCC optimize a*a*a*a*a*a to (a*a*a)*(a*a*a)?
...a,2) by compiling it into a*a , but the call pow(a,6) is not optimized and will actually call the library function pow , which greatly slows down the performance. (In contrast, Intel C++ Compiler , executable icc , will eliminate the library call for pow(a,6) .)
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Trusting all certificates using HttpClient over HTTPS
...SSLSocketFactory
itself. Some clues can be found in this post Custom SSL handling stopped working on Android 2.2 FroYo.
An example is like ...
import java.io.IOException;
import java.net.Socket;
import java.net.UnknownHostException;
import java.security.KeyManagementException;
import java.securi...
Find the IP address of the client in an SSH session
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@cwd i want to replace the ip in this command "iptables -A INPUT -s 93.203.118.251 -p tcp --destination-port 443 -j DROP" is that possible?
– wutzebaer
Aug 5 '15 at 13:00
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Why Collections.sort uses merge sort instead of quicksort?
...es, as there is no notion of
identity as distinct from (value) equality. And the possibility of
quadratic behavior was deemed not to be a problem in practice for
Bentely and McIlroy's implementation (or subsequently for Dual Pivot
Quicksort), which is why these QuickSort variants were used f...