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What's a concise way to check that environment variables are set in a Unix shell script?
... original answer is more consistent in its syntax.
– fast tooth
Jul 14 '16 at 0:35
4
This does no...
Multiple Updates in MySQL
...onclusion is that the variant with case statement turns out to be twice as fast as two other variants, but it's quite hard to write correct and injection-safe code for it, so I personally stick to the simplest approach: using transactions.
Edit: Findings of Dakusan prove that my performance estimat...
How safe is it to store sessions with Redis?
...s. All operations are performed in memory, and so reads and writes will be fast.
The second aspect is persistence of session state. Redis gives you a lot of flexibility in how you want to persist session state to your hard-disk. You can go through http://redis.io/topics/persistence to learn more, ...
Undo a Git merge that hasn't been pushed yet
...
@JohnBachir: As long as the "merge" isn't really a fast forward, it will result in a new commit that is at the top of the log, and this commit has two parents (or more than 2 if you do an octopus merge). If you remove this one merge commit, then all of the older commits that ...
How to convert Linux cron jobs to “the Amazon way”?
...
We decided to go with the second option, simply because it's brilliantly fast and we already had experience with webservers running these cronjobs (in our pre-AWS era).
Of course, this solution is meant specifically for replacing the traditional one-node cronjob approach, where timing is the deci...
What's the difference between RouteLink and ActionLink in ASP.NET MVC?
...ows there's just too many possibilities. MS guys should only implement the fastest. But people rather use the fancy lambda slowest one.
– Robert Koritnik
Oct 21 '09 at 21:10
...
How do I empty an array in JavaScript?
...you only reference the array by its original variable A.
This is also the fastest solution.
This code sample shows the issue you can encounter when using this method:
var arr1 = ['a','b','c','d','e','f'];
var arr2 = arr1; // Reference arr1 by another variable
arr1 = [];
console.log(arr2); // Ou...
LINQ Ring: Any() vs Contains() for Huge Collections
...because you can pass it a custom predicate, but Contains might be slightly faster because it doesn't need to perform a delegate invocation for each element.
– LukeH
Dec 14 '10 at 23:45
...
What is the difference between dict.items() and dict.iteritems() in Python2?
... former takes more space and time initially, but accessing each element is fast, whereas the second takes less space and time initially, but a bit more time in generating each element.
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impro...
Randomize a List
...s the much criticised System.Random method to select swap candidates. It's fast but not as random as it should be. If you need a better quality of randomness in your shuffles use the random number generator in System.Security.Cryptography like so:
using System.Security.Cryptography;
...
public stat...