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postgresql COUNT(DISTINCT …) very slow
...ount int not null), using triggers. But your write performance will suffer and if you update multiple x values in single transaction then you'd need to do this in some explicit order to avoid possible deadlock.
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Get ffmpeg information in friendly way
...t information you want it to display (with the -show_format, -show_packets and -show_streams options) or it'll just give you blank output (like you mention in one of your comments).
For example, ffprobe -v quiet -print_format json -show_format -show_streams somefile.asf would yield something like t...
Why doesn't Haskell's Prelude.read return a Maybe?
...e shuffle. There should be such a function, although one is easy to write (and there are zillions of very similar versions floating around many codebases).
See also this discussion.
Personally, I use the version from the safe package.
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C++11 range based loop: get item by value or reference to const
... with copies.
Choose auto &x when you want to work with original items and may modify them.
Choose auto const &x when you want to work with original items and will not modify them.
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How to concatenate and minify multiple CSS and JavaScript files with Grunt.js (0.3.x)
Note: This question is only relevant for Grunt 0.3.x and has been left for reference. For help with the latest Grunt 1.x release please see my comment below this question.
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Argparse: Required argument 'y' if 'x' is present
...ts of options.
The simplest way to deal with this would be:
if args.prox and (args.lport is None or args.rport is None):
parser.error("--prox requires --lport and --rport.")
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Why are `private val` and `private final val` different?
I used to think that private val and private final val are same, until I saw section 4.1 in Scala Reference:
2 Answers
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javascript scroll event for iPhone/iPad?
... stops panning—an onscroll event is generated when the page stops moving and redraws—as shown in Figure 6-1.
Similarly, scroll with 2 fingers fires onscroll only after you've stopped scrolling.
The usual way of installing the handler works e.g.
window.addEventListener('scroll', f...
EF LINQ include multiple and nested entities
... bool operator other list
Update
To learn more, download LinqPad and look through the samples.
I think it is the quickest way to get familiar with Linq and Lambda.
As a start - the difference between Select and Include is that that with a Select you decide what you want to return (aka pro...
Insert/Update Many to Many Entity Framework . How do I do it?
I'm using EF4 and new to it. I have a many to many in my project and cannot seem to work out how to insert or update. I have build a small project just to see how it should be coded.
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