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Why are joins bad when considering scalability?
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Scalability is all about pre-computing (caching), spreading out, or paring down the repeated work to the bare essentials, in order to minimize resource use per work unit. To scale well, you don't do anything you don't need to in volume, and...
Why is an int in OCaml only 31 bits?
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This is called a tagged pointer representation, and is a pretty common optimization trick used in many different interpreters, VMs and runtime systems for decades. Pretty much every Lisp implementation uses them, many Smalltalk VMs, m...
How do I (or can I) SELECT DISTINCT on multiple columns?
I need to retrieve all rows from a table where 2 columns combined are all different. So I want all the sales that do not have any other sales that happened on the same day for the same price. The sales that are unique based on day and price will get updated to an active status.
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How do I get currency exchange rates via an API such as Google Finance? [closed]
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Thanks for all your answers.
Free currencyconverterapi:
Rates updated every 30 min
API key is now required for the free server.
A sample conversion URL is: http://free.currencyconverterapi.com/api/v5/convert?q=EUR_USD&compact=y
F...
Using Regex to generate Strings rather than match them
...elps me to generate loads of data for performance testing. It would be really cool to be able to specify a regex for Strings so that my generator spits out things which match this. Is there something out there already baked which I can use to do this? Or is there a library which gets me most of...
Can I use my existing git repo with openshift?
... openshift repo with your local bitbucket clone. You do that by issuing locally:
git merge openshift/master -s recursive -X ours
With this command you tell git to merge the master branch in the openshift git repo with your local git repo. You tell it to merge using the recursive merging strategy a...
Is there an MD5 Fixed Point where md5(x) == x?
...ng. Assuming that the MD5 sum of any string is uniformly distributed over all possible sums, then the probability that any given 128-bit string is a fixed point is 1/2128.
Thus, the probability that no 128-bit string is a fixed point is (1 − 1/2128)2128, so the probability that there is a fixed ...
Capistrano - clean up old releases
Usually when using capistrano, I will go and manually delete old releases from a deployed application. I understand that you can run cap deploy:cleanup but that still leaves 5 releases. Is this it's intended purpose? Is there another way to cleanup old releases to just 1 previous deploy?
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Trying to embed newline in a variable in bash [duplicate]
...ar ) # Do not use double quotes "$var"
echo "$p"
Output is the same for all
a
b
c
Special thanks to contributors of this answer: kevinf, Gordon Davisson, l0b0, Dolda2000 and tripleee.
EDIT
See also BinaryZebra's answer providing many details.
Abhijeet Rastogi's answer and Dimitry's answer...
In C#, what is the difference between public, private, protected, and having no access modifier?
All my college years I have been using public , and would like to know the difference between public , private , and protected ?
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