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When to add what indexes in a table in Rails
...add:
add_index :photos, [:created_at, :version]
Note:
An index takes up extra space on the disk and makes it slower to create and update each record, because it has to rebuild each index.
Credit:
https://tomafro.net/2009/08/using-indexes-in-rails-choosing-additional-indexes, rails - created_at ...
What exactly does an #if 0 … #endif block do?
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@Dennis, I get foo.c:3: unterminated string or character constant from gcc, what're you using?
– David X
May 22 '10 at 2:29
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Is VB really case insensitive?
...s, when programming you can think of VB.NET as case-insensitive apart from string-comparisons, XML, and a few other situations...
I think you're interested in what's under the hood. Well, the .NET Common Language Runtime is case-sensitive, and VB.NET code relies on the runtime, so you can see it mu...
List goals/targets in GNU make that contain variables in their definition
...utput from make -pn (i.e. make --print-data-base --dry-run)? It prints out all the variables, rules, implicit rules and which commands will be run in laborious detail.
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Elegant ways to support equivalence (“equality”) in Python classes
When writing custom classes it is often important to allow equivalence by means of the == and != operators. In Python, this is made possible by implementing the __eq__ and __ne__ special methods, respectively. The easiest way I've found to do this is the following method:
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Weighted random numbers
...a weighted random numbers. I'm currently just banging my head against the wall and cannot figure this out.
7 Answers
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How can I select item with class within a DIV?
...ll it will probably search in the same fashion and in your case perform an extra check. Possible that native implementations do the same.
– davin
Aug 3 '11 at 22:00
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How to handle many-to-many relationships in a RESTful API?
...00:00:00Z',
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This solution relies on REST resources only. Although some extra calls may be necessary to get data from players, teams or their relationship, all HTTP methods are easily implemented. POST, PUT, DELETE are simple and straightforward.
Whenever a relationship is created, updated or de...
How to include() all PHP files from a directory?
...t because this question was about including everything in a directory - usually this would be in different directories: eg DataClass defined in BE directory and BL.class.php defined in BL directory.
– Carmageddon
May 13 '13 at 15:52
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Select count(*) from multiple tables
How can I select count(*) from two different tables (call them tab1 and tab2 ) having as result:
18 Answers
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