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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...
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 do I get the RootViewController from a pushed controller?
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:) ty. It still seems hacky - :) I really wanted an "official" member to do the job, something like self.navigationController.rootViewController, but alas, no such thing..
– bobobobo
Nov 25 '09 at 2:21
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Give examples of functions which demonstrate covariance and contravariance in the cases of both over
...List<? super String> contravariantList = aList;
You can now access all methods of covariantList that doesn't take a generic parameter (as it must be something "extends Object"), but getters will work fine (as the returned object will always be of type "Object")
The opposite is true for cont...
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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Github Windows 'Failed to sync this branch'
...to those stuck: If GitHub for Windows is crashing but in Git Shell you see all green and this git status message "Your branch is ahead of 'origin/master' by 1 commit. (use "git push" to publish your local commits)". Entering git push fixed this for me. I restarted GitHub for Windows and sync finall...
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 ...
How to reposition Chrome Developer Tools
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If you can't open the dock at all, try Ctrl+Shift+I -- but if your window is a popup, I don't think docking even works.
– Noumenon
Oct 4 '16 at 13:35
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How to disable scrolling in UITableView table when the content fits on the screen
...h, not subclassed from UITableViewController ) that 80% of the time are small and will fit on the screen. When the table fits on the screen, I'd like to disable scrolling, to make it a bit cleaner. But if the table goes off the screen (when rows are later added to it), I'd like to enable scrollin...