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INNER JOIN vs LEFT JOIN performance in SQL Server
...O(1) for the hashtable.
But change this query to be on the ID column instead of Name and you'll see a very different story. In that case, it does nested loops for both queries, but the INNER JOIN version is able to replace one of the clustered index scans with a seek - meaning that this will liter...
How do I find the duplicates in a list and create another list with them?
...= []
for x in a:
if x not in seen:
uniq.append(x)
seen.add(x)
or, more concisely:
seen = set()
uniq = [x for x in a if x not in seen and not seen.add(x)]
I don't recommend the latter style, because it is not obvious what not seen.add(x) is doing (the set add() method al...
What’s the difference between ScalaTest and Scala Specs unit test frameworks?
...ld go with operator notation, and ended up with matcher expressions that read very much like English sentences, with spaces between the words. Specs matcher syntax runs words together more with camel case.
Specs has more matchers than ScalaTest, and that I think reflects a difference in design atti...
Simplest PHP example for retrieving user_timeline with Twitter API version 1.1
...ails you want. For me, it didn't matter, because I just wanted to make a load of block requests to get rid of spam followers. The point is you are going to get yourself a set of unique keys to use for your application.
So, the point of creating an application is to give yourself (and Twitter) a set ...
What is the difference D3 datum vs. data?
...
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What is the dependency inversion principle and why is it important?
...important, in short: changes are risky, and by depending on a concept instead of on an implementation, you reduce the need for change at call sites.
Effectively, the DIP reduces coupling between different pieces of code. The idea is that although there are many ways of implementing, say, a logging ...
Maintain the aspect ratio of a div with CSS
...
Just create a wrapper <div> with a percentage value for padding-bottom, like this:
.demoWrapper {
padding: 10px;
background: white;
box-sizing: border-box;
resize: horizontal;
border: 1px dashed;
overflow: auto;
max-width: 100%;
height: calc(100vh - 16px);
}
di...
Read/write to Windows registry using Java
How is it possible to read/write to the Windows registry using Java?
24 Answers
24
...
How to implement a rule engine?
...on.Call(left, method, right);
}
}
Note that I used 'GreaterThan' instead of 'greater_than' etc. - this is because 'GreaterThan' is the .NET name for the operator, therefore we don't need any extra mapping.
If you need custom names you can build a very simple dictionary and just translate all op...
Trusting all certificates using HttpClient over HTTPS
...ed a question regarding the HttpClient over Https ( found here ). I've made some headway, but I've run into new issues. As with my last problem, I can't seem to find an example anywhere that works for me. Basically, I want my client to accept any certificate (because I'm only ever pointing to one...