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Can PostgreSQL index array columns?
...tage from the original Berkeley design of Postgres and very hard to change now. And it's generally working just fine. Here is a thread on pgsql-bugs with Tom Lane commenting on this.
Some PostGis functions (like ST_DWithin()) seem to violate this principal, but that is not so. Those functions are r...
git diff file against its last change
...possible to get git to produce a diff between a specific file as it exists now, and as it existed before the last commit that changed it?
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Using HTML5/JavaScript to generate and save a file
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If you know the source url that you want to download this is the best solution!
– sidonaldson
Aug 16 '13 at 14:58
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Why does document.querySelectorAll return a StaticNodeList rather than a real Array?
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I don't know why it returns a node list instead of an array, maybe because like getElementsByTagName it will update the result when you update the DOM. Anyway a very simple method to transform that result in a simple array is:
Array....
Change navbar color in Twitter Bootstrap
...theme:
TWBSColor - Generate your own Bootstrap navbar
[Update]: TWBSColor now generates SCSS/SASS/Less/CSS code.
[Update]: From now, you can use Less as the default language provided by TWBSColor
[Update]: TWBSColor now supports drop down menus colorization
[Update]: TWBSColor now allows to choos...
What is a race condition?
...read scheduling algorithm can swap between threads at any time, you don't know the order in which the threads will attempt to access the shared data. Therefore, the result of the change in data is dependent on the thread scheduling algorithm, i.e. both threads are "racing" to access/change the data....
Total width of element (including padding and border) in jQuery
...t the time where not adequate by themselves to calculate the whole width.
Now, as J-P correctly states, jQuery has the functions outerWidth and outerHeight which include the border and padding by default, and also the margin if the first argument of the function is true
[Original answer]
The w...
Is < faster than
...- B < 0
A = B --> A - B = 0
A > B --> A - B > 0
Now, when A < B the subtraction has to borrow a high-bit for the subtraction to be correct, just like you carry and borrow when adding and subtracting by hand. This "borrowed" bit was usually referred to as the carry bit a...
Odd behavior when Java converts int to byte?
...resent it as an int (32 bits) you simply copy the 1 to the left 24 times.
Now, one way to read a negative two's complement number is to start with the least significant bit, move left until you find the first 1, then invert every bit afterwards. The resulting number is the positive version of that ...
Subtract 7 days from current date
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use dateByAddingTimeInterval method:
NSDate *now = [NSDate date];
NSDate *sevenDaysAgo = [now dateByAddingTimeInterval:-7*24*60*60];
NSLog(@"7 days ago: %@", sevenDaysAgo);
output:
7 days ago: 2012-04-11 11:35:38 +0000
Hope it helps
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