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How do MySQL indexes work?
I am really interested in how MySQL indexes work, more specifically, how can they return the data requested without scanning the entire table?
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Android: How can I get the current foreground activity (from a service)?
...atePendingResult()) that the service invokes
Have the activity register a callback or listener object with the service via bindService(), and have the service call an event method on that callback/listener object
Send an ordered broadcast Intent to the activity, with a low-priority BroadcastReceiver...
Error in plot.new() : figure margins too large in R
I'm new to R but I've made numerous correlation plots with smaller data sets. However, when I try to plot a large dataset (2gb+), I can produce the plot just fine, but the legend doesn't show up. Any advice? or alternatives?
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What is Persistence Context?
...erence/en/html/architecture.html
In Java EE, a persistence context is normally accessed via an EntityManager.
http://docs.oracle.com/javaee/6/api/javax/persistence/EntityManager.html
The various states an entity can have and the transitions between these are described below:
http://docs.jboss.or...
What is reflection and why is it useful?
... say you have an object of an unknown type in Java, and you would like to call a 'doSomething' method on it if one exists. Java's static typing system isn't really designed to support this unless the object conforms to a known interface, but using reflection, your code can look at the object and fin...
How much size “Null” value takes in SQL Server
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The smallest addressable unit of memory in most computer systems is one byte (typically 8 bits). So in reality, a bit takes a byte. Great answer Mark: +1.
– JohnB
Sep 16 '10 at 22:23
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Fatal error: Class 'ZipArchive' not found in
I have a problem that I install 'Archive_Zip 0.1.1' on Linux server, but when I try to run the script to create the zip file it gives the fatal error
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Should Github be used as a CDN for javascript libraries? [closed]
.... The last one means less total work for everybody, so it's clearly a win all around, and is more likely the more often we (developers) rely on the CDNs to serve our javascript.
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How can I install pip on Windows?
pip is a replacement for easy_install . But should I install pip using easy_install on Windows? Is there a better way?
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Why use make over a shell script?
...t would be a lot more work (explicitly checking the last-modified dates on all the files, etc.) The only obvious alternative with a shell script is to rebuild everything every time. For tiny projects this is a perfectly reasonable approach, but for a big project a complete rebuild could easily take ...