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What is the purpose of shuffling and sorting phase in the reducer in Map Reduce Programming?
...e reduce phase has shuffling, sorting and reduce as its sub-parts. Sorting is a costly affair.
9 Answers
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What exactly is metaprogramming?
...edge of itself or can manipulate itself.
In languages like C#, reflection is a form of metaprogramming since the program can examine information about itself. For example returning a list of all the properties of an object.
In languages like ActionScript, you can evaluate functions at runtime to c...
Difference between := and = operators in Go
What is the difference between the = and := operators, and what are the use cases for them? They both seem to be for an assignment?
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What is the difference between Amazon SNS and Amazon SQS?
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SNS is a distributed publish-subscribe system. Messages are pushed to subscribers as and when they are sent by publishers to SNS.
SQS is distributed queuing system. Messages are NOT pushed to receivers. Receivers have to poll o...
Why is the order in dictionaries and sets arbitrary?
I don't understand how looping over a dictionary or set in python is done by 'arbitrary' order.
6 Answers
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Creating range in JavaScript - strange syntax
I've run into the following code in the es-discuss mailing list:
4 Answers
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How to shorten my conditional statements
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Put your values into an array, and check if your item is in the array:
if ([1, 2, 3, 4].includes(test.type)) {
// Do something
}
If a browser you support doesn't have the Array#includes method, you can use this polyfill.
Short explanation of the ~ tilde shortcut:
U...
Is there a Python equivalent of the C# null-coalescing operator?
...me default value"
Ok, it must be clarified how the or operator works. It is a boolean operator, so it works in a boolean context. If the values are not boolean, they are converted to boolean for the purposes of the operator.
Note that the or operator does not return only True or False. Instead, i...
Android SQLite DB When to Close
I am working with a SQLite database on android. My database manager is a singleton and right now opens a connection to the database when it is initialized. It is safe to leave the database open the entire time so that when someone calls my class to work with the database it is already open? Or shoul...
What is the optimal length for an email address in a database?
Here is an extracted portion of my query, reflecting the EMAIL_ADDRESS column data type and property:
8 Answers
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