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RabbitMQ and relationship between channel and connection
...nections.
You can use one Channel for everything. However, if you have multiple threads, it's suggested to use a different Channel for each thread.
Channel thread-safety in Java Client API Guide:
Channel instances are safe for use by multiple threads. Requests into
a Channel are serialized, ...
Disabling swap files creation in vim
...ing which is a large part of vim use for a lot of people, it seems like an extra bookeeping job better left out. I personally prefer for all jobs to just have no swaps or other auto-backups. If I really need to develop something, I'd rather have a more high level framework to protect me, preferably ...
Using union and order by clause in mysql
...organize.
But this way has the advantage of being fast, not introducing extra variables, and making it easy to separate out each query including the sort. The ability to add a limit is simply an extra bonus.
And of course feel free to turn the union all into a union and add a sort for the whole...
How to call getClass() from a static method in Java?
...putStream when used in a MapReduce.
public static InputStream getResource(String resource) throws Exception {
ClassLoader cl = Thread.currentThread().getContextClassLoader();
InputStream is = cl.getResourceAsStream(resource);
return is;
}
...
Why should I use a pointer rather than the object itself?
...eir destructors called once they go out of scope. For example:
{
std::string s;
}
// s is destroyed here
On the other hand, if you use a pointer dynamically allocated, its destructor must be called manually. delete calls this destructor for you.
{
std::string* s = new std::string;
}
dele...
Extract month and year from a zoo::yearmon object
...an extract the date parts as required:
> format(date1, "%b") ## Month, char, abbreviated
[1] "Mar"
> format(date1, "%Y") ## Year with century
[1] "2012"
> format(date1, "%m") ## numeric month
[1] "03"
These are returned as characters. Where appropriate, wrap in as.numeric() if you want t...
If vs. Switch Speed
...ector to look at the code produced, you will see that for huge switches on strings, the compiler will actually generate code that uses a hash table to dispatch these. The hash table uses the strings as keys and delegates to the case codes as values.
This has asymptotic better runtime than lots of c...
Use of alloc init instead of new
...selected ones are:
new doesn't support custom initializers (like initWithString)
alloc-init is more explicit than new
General opinion seems to be that you should use whatever you're comfortable with.
share
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What's wrong with nullable columns in composite primary keys?
...s version the "ext" part of the tuple is NOT NULL but defaults to an empty string -- which is semantically (and practically) different from a NULL. A NULL is an unknown, whereas an empty string is a deliberate record of "something not being present". In other words, "empty" and "null" are different ...
Check if a value is an object in JavaScript
...
@Tresdin The best way is to run Object.prototype.toString.call(yourVar), being yourVar what you need to inspect. In case of arrays, Object.prototype.toString.call([1,2]) returns [object Array]
– Jose Rui Santos
Feb 25 '16 at 9:48
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