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mongo group query how to keep fields
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Just a quick update if one faces the same issue with documents with numerous fields.
One can use the power of combining the $replaceRoot pipeline stage and the $mergeObjects pipeline operator.
db.users.aggregate([
{
$group: {
_id: '$n...
Java HashMap performance optimization / alternative
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Much much better. The old method tailed off very quickly while the new one keeps up a good throughput.
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Keep-alive header clarification
I was asked to build a site , and one of the co-developer told me That I would need to include the keep-alive header.
1 An...
Calling class staticmethod within the class body?
...al function, I had no idea of the specifics. In the spirit of teaching someone to fish rather than giving them a fish, this is what I did to investigate and find that out (a C&P from my Python session):
>>> class Foo(object):
... @staticmethod
... def foo():
... return ...
How to get random value out of an array?
...nction to select a random key from your array like below.
$array = array("one", "two", "three", "four", "five", "six");
echo $array[array_rand($array, 1)];
or you could use the rand and count functions to select a random index.
$array = array("one", "two", "three", "four", "five", "six");
echo...
android.view.InflateException: Binary XML file line #12: Error inflating class
...eption when trying to inflate an imageview loading a drawable resource. If one of this resources has a high pixel resolution it would take a lot of memory causing then an inflate exception.
So basically verify that the pixel resolution in your drawables images are just the minimum necessary for you...
static files with express.js
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If there is only ONE parameter - then express.static expects that one parameter to be path....
– Seti
Dec 16 '16 at 8:21
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Rails 4 LIKE query - ActiveRecord adds quotes
... edited Feb 13 '17 at 23:08
typeoneerror
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answered Oct 1 '13 at 0:07
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How to append rows to an R data frame
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Update
Not knowing what you are trying to do, I'll share one more suggestion: Preallocate vectors of the type you want for each column, insert values into those vectors, and then, at the end, create your data.frame.
Continuing with Julian's f3 (a preallocated data.frame) as the fa...
How to show all parents and subclasses of a class in IntelliJ IDEA?
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One more thing - this still doesn't behave the same as Eclipse's quick type hierarchy: In Eclipse, when you hover over a class in the hierarchy, pressing <Enter> will open the source file with the class; in IntelliJ, yo...