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How efficient is locking an unlocked mutex? What is the cost of a mutex?
In a low level language (C, C++ or whatever): I have the choice in between either having a bunch of mutexes (like what pthread gives me or whatever the native system library provides) or a single one for an object.
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Why does Oracle 9i treat an empty string as NULL?
I know that it does consider ' ' as NULL , but that doesn't do much to tell me why this is the case. As I understand the SQL specifications, ' ' is not the same as NULL -- one is a valid datum, and the other is indicating the absence of that same information.
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When should I use Struct vs. OpenStruct?
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With an OpenStruct, you can arbitrarily create attributes. A Struct, on the other hand, must have its attributes defined when you create it. The choice of one over the other should be based primarily on whether you need to be able to add attributes late...
Compare JavaScript Array of Objects to Get Min / Max
I have an array of objects and I want to compare those objects on a specific object property. Here's my array:
16 Answers
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Are there any worse sorting algorithms than Bogosort (a.k.a Monkey Sort)? [closed]
My co-workers took me back in time to my University days with a discussion of sorting algorithms this morning. We reminisced about our favorites like StupidSort , and one of us was sure we had seen a sort algorithm that was O(n!) . That got me started looking around for the "worst" sorting algor...
XPath to find elements that does not have an id or class
How can I get all tr elements without id attribute?
4 Answers
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How can I randomize the lines in a file using standard tools on Red Hat Linux?
...l -MList::Util -e 'print List::Util::shuffle <>'
It uses a module, but the module is part of the Perl code distribution. If that's not good enough, you may consider rolling your own.
I tried using this with the -i flag ("edit-in-place") to have it edit the file. The documentation suggests i...
Windows XP or later Windows: How can I run a batch file in the background with no window displayed?
I know I have already answered a similar question ( Running Batch File in background when windows boots up ), but this time I need to launch a batch:
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Does a UNIQUE constraint automatically create an INDEX on the field(s)?
... Using SHOW INDEXES FROM customer you can see your unique keys are in fact B-tree type indexes.
A composite index on (email, user_id) is enough, you don't need a separate index on email only - MySQL can use leftmost parts of a composite index. There may be some border cases where the size of an ind...
Why is '397' used for ReSharper GetHashCode override?
...ed up the development process. When you use it to override the equality members of a class, the code-gen it produces for GetHashCode() looks like:
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