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COUNT(*) vs. COUNT(1) vs. COUNT(pk): which is better? [duplicate]
...T(field) or COUNT(*), and stick with it consistently, and if your database allows COUNT(tableHere) or COUNT(tableHere.*), use that.
In short, don't use COUNT(1) for anything. It's a one-trick pony, which rarely does what you want, and in those rare cases is equivalent to count(*)
Use count(*) fo...
Clone Object without reference javascript [duplicate]
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This is really very good reply. I got the exact solution for my problem. Thanks.
– Sumit Tawal
Jul 10 '15 at 12:26
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Rebuild or regenerate 'ic_launcher.png' from images in Android Studio
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Beware using Asset Studio in Android Studio automatically adds padding, shrinking the resulting image.
– Androidcoder
Jun 16 '15 at 17:03
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Task vs Thread differences [duplicate]
I'm new to parallel programming. There are two classes available in .NET: Task and Thread .
4 Answers
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What is a “cache-friendly” code?
...her end of the memory spectrum (DRAM), the memory is very cheap (i.e. literally millions of times cheaper) but takes hundreds of cycles after a request to receive the data. To bridge this gap between super fast and expensive and super slow and cheap are the cache memories, named L1, L2, L3 in decre...
Caveats of select/poll vs. epoll reactors in Twisted
...ePoll is a natural replacement for Select and Poll based networking, especially with Twisted. Which makes me paranoid, its pretty rare for a better technique or methodology not to come with a price.
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Eclipse: The declared package does not match the expected package
...es of the project don't seem to be what Eclipse expects. The package names all have a prefix:
13 Answers
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How can I pretty-print JSON in a shell script?
...ou can use
curl http://my_url/ | python -m json.tool
For convenience in all of these cases you can make an alias:
alias prettyjson='python -m json.tool'
For even more convenience with a bit more typing to get it ready:
prettyjson_s() {
echo "$1" | python -m json.tool
}
prettyjson_f() {...
Efficiency of Java “Double Brace Initialization”?
...2$8.class
2009/05/27 16:35 2,022 DemoApp2$9.class
These are all classes which were generated when I was making a simple application, and used copious amounts of anonymous inner classes -- each class will be compiled into a separate class file.
The "double brace initialization", as al...
Ruby on Rails generates model field:type - what are the options for field:type?
...nother model's ID. I'd look it up myself, but I haven't figured out, among all my Ruby on Rails documentation links, how to find the definitive source.
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