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What's wrong with nullable columns in composite primary keys?
ORACLE does not permit NULL values in any of the columns that comprise a primary key. It appears that the same is true of most other "enterprise-level" systems.
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Error handling in Bash
What is your favorite method to handle errors in Bash?
The best example of handling errors I have found on the web was written by William Shotts, Jr at http://www.linuxcommand.org .
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How do you use bcrypt for hashing passwords in PHP?
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bcrypt is a hashing algorithm which is scalable with hardware (via a configurable number of rounds). Its slowness and multiple rounds ensures that an attacker must deploy massive funds and hardware to be able to crack your passwords. Add to that per-...
Ukkonen's suffix tree algorithm in plain English
I feel a bit thick at this point. I've spent days trying to fully wrap my head around suffix tree construction, but because I don't have a mathematical background, many of the explanations elude me as they start to make excessive use of mathematical symbology. The closest to a good explanation that ...
Creating a blurring overlay view
...sic app of the new iOS, we can see an album cover behind a view that blurs it.
25 Answers
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Can every recursion be converted into iteration?
A reddit thread brought up an apparently interesting question:
17 Answers
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Why do most fields (class members) in Android tutorial start with `m`?
I know about camel case rules, but I'm confused with this m rule. What does it stand for? I'm a PHP developer. "We" use first letters of variables as indication of type, like 'b' for boolean, 'i' for integer and so on.
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elasticsearch v.s. MongoDB for filtering application [closed]
This question is about making an architectural choice prior to delving into the details of experimentation and implementation. It's about the suitability, in scalability and performance terms, of elasticsearch v.s. MongoDB, for a somewhat specific purpose.
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C: What is the difference between ++i and i++?
...eing incremented.
i = 1;
j = i++;
(i is 2, j is 1)
For a for loop, either works. ++i seems more common, perhaps because that is what is used in K&R.
In any case, follow the guideline "prefer ++i over i++" and you won't go wrong.
There's a couple of comments regarding the efficiency of +...
How to make a whole 'div' clickable in html and css without JavaScript? [duplicate]
I want to make it so that a whole div is clickable and links to another page when clicked without JavaScript and with valid code/markup.
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