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JOIN queries vs multiple queries
... depending on whether or not you're planning on scaling. Cuz when facebook started out I'm sure they had those kind of queries, but had scaling in mind and went for the more efficient albeit possibly more complex solution.
– dudewad
Jul 4 '13 at 23:04
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Correct way to use StringBuilder in SQL
... listed some_appropriate_size in the StringBuilder constructor, so that it starts out with enough capacity for the full content we're going to append. The default size used if you don't specify one is 16 characters, which is usually too small and results in the StringBuilder having to do reallocatio...
Measuring function execution time in R
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Another possible way of doing this would be to use Sys.time():
start.time <- Sys.time()
...Relevent codes...
end.time <- Sys.time()
time.taken <- end.time - start.time
time.taken
Not the most elegant way to do it, compared to the answere above , but definitely a way to do it.
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Multiple contexts with the same path error running web service in Eclipse using Tomcat
...e the class, I created the web service with Apache Axis2. When I click the start server button in eclipse it gives an error message:
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How do I get the time difference between two DateTime objects using C#?
...ts me a TimeSpan that will tell me the diff.
Here's an example:
DateTime start = DateTime.Now;
// Do some work
TimeSpan timeDiff = DateTime.Now - start;
timeDiff.TotalMilliseconds;
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improv...
Simultaneously merge multiple data.frames in a list
...e all columns, we can use select helpers from tidyselect and
choose (as we start from .x all .x columns are kept):
eat(x, list(y,z), starts_with("l") ,.by = "i")
# # A tibble: 3 x 3
# i j l
# <chr> <int> <int>
# 1 a 1 9
# 2 b 2 NA
# 3 c ...
How to call asynchronous method from synchronous method in C#?
...then you'll deadlock even with the nested context. In that case, you could start the async method on the thread pool:
var task = Task.Run(async () => await MyAsyncMethod());
var result = task.WaitAndUnwrapException();
However, this solution requires a MyAsyncMethod that will work in the thread p...
What does jquery $ actually return?
...are store as property of the object, their property name are index numbers start from 0,
thus could be accessed by index, start from 0,
after get the original element, you can treat it as if get by document.getElementXxx().
Wrap an original element to a jquery object
After get the original element...
Push Notifications in Android Platform
...ion - Does Android support near real time push notification? )
I recently started playing with MQTT http://mqtt.org for Android as a way of doing this sort of thing (i.e. push notification that is not SMS but data driven, almost immediate message delivery, not polling, etc.)
I have a blog post wit...
Adding minutes to date time in PHP
...ns, I get 2012-04-18 00:00 as a result. ` $time = new DateTime($_REQUEST['start']); $time->add(new DateInterval('P' . $duration . 'M')); $endTime = $time->format('Y-m-d H:i'); echo $endTime; ` Applogies for the formatting, it appears I can't work this out either today ^_^
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