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How do you clear a slice in Go?
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It all depends on what is your definition of 'clear'. One of the valid ones certainly is:
slice = slice[:0]
But there's a catch. If slice elements are of type T:
var slice []T
then enforcing len(slice) to be zero, by the a...
Java `final` method: what does it promise?
...method can't be overridden (for object scope) or hidden (for static). This allows the original developer to create functionality that cannot be changed by subclasses, and that is all the guarantee it provides.
This means that if the method relies on other customizable components like non-public fie...
Shards and replicas in Elasticsearch
...e need to create an index.
When you create an index (an index is automatically created when you index the first document as well) you can define how many shards it will be composed of. If you don't specify a number it will have the default number of shards: 5 primaries. What does it mean?
It mean...
Error in plot.new() : figure margins too large in R
I'm new to R but I've made numerous correlation plots with smaller data sets. However, when I try to plot a large dataset (2gb+), I can produce the plot just fine, but the legend doesn't show up. Any advice? or alternatives?
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Posting a File and Associated Data to a RESTful WebService preferably as JSON
...as JSON. Part of this application requires the client to upload a file (usually an image) as well as information about the image.
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Storing time-series data, relational or non?
... description, the actual PK is (Device, Metric, DateTime). (Please don't call it TimeStamp, that means something else, but that is a minor issue.) The uniqueness of the row is identified by:
(Device, Metric, DateTime)
The Id column does nothing, it is totally and completely redundant.
A...
What is the reason for having '//' in Python? [duplicate]
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I actually like this style better... I can remember in atleast one language I've used (VB?) the differentiating factor was / vs \ ... but I could never remember which was which!
– Matthew Scharley
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What is Persistence Context?
...erence/en/html/architecture.html
In Java EE, a persistence context is normally accessed via an EntityManager.
http://docs.oracle.com/javaee/6/api/javax/persistence/EntityManager.html
The various states an entity can have and the transitions between these are described below:
http://docs.jboss.or...
Is a view faster than a simple query?
...es.
Update: At least three people have voted me down on this one. With all due respect, I think that they are just wrong; Microsoft's own documentation makes it very clear that Views can improve performance.
First, simple views are expanded in place and so do not directly contribute to performa...
How to swap keys and values in a hash
...;:b, 3=>:c}
BUT...
If you have duplicate values, invert will discard all but the last occurrence of your values (because it will keep replacing new value for that key during iteration). Likewise, key will only return the first match:
{a: 1, b: 2, c: 2}.key(2)
=> :b
{a: 1, b: 2, c: 2}.inv...