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When and why are database joins expensive?
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Denormalising to improve performance? It sounds convincing, but it doesn't hold water.
Chris Date, who in company with Dr Ted Codd was the original proponent of the relational data model, ran out of patience with misinformed ar...
Differences between INDEX, PRIMARY, UNIQUE, FULLTEXT in MySQL?
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Differences
KEY or INDEX refers to a normal non-unique index. Non-distinct values for the index are allowed, so the index may contain rows with identical values in all columns of the index. These indexes don't enforce any restraints on you...
Get jQuery version from inspecting the jQuery object
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You can use either $().jquery; or $.fn.jquery which will return a string containing the version number, e.g. 1.6.2.
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How to change package name of an Android Application
My keystore is corrupt, therefore the Android Market is requiring me to rename the app and resubmit it. However, whenever I go to edit the package names in Manifest and throughout the files, it gives me tons of errors.
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Get the real width and height of an image with JavaScript? (in Safari/Chrome)
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var pic_real_width, pic_real_height;
$("<img/>") // Make in memory copy of image to avoid css issues
.attr("src", $(img).attr("src"))
.load(function() {
pic_real_width = this.width; // Note: $(this).width() will not
pic_real_height = this.height; // work for in ...
What is thread contention?
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Essentially thread contention is a condition where one thread is waiting for a lock/object that is currently being held by another thread. Therefore, this waiting thread cannot use that object until the other thread has unlocked that particular object.
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TypeError: unhashable type: 'dict'
This piece of code is giving me an error unhashable type: dict can anyone explain me what is the solution
2 Answers
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Why use Ruby instead of Smalltalk? [closed]
...n Ruby and Smalltalk -- maglev is a testament to that. Despite having a more unusual syntax, Smalltalk has all (if not more) of the object-oriented beauty of Ruby.
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Which is more preferable to use: lambda functions or nested functions ('def')?
...ons but sometimes use nested functions that seem to provide the same behavior.
16 Answers
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Rails 4: assets not loading in production
...trying to put my app into production and image and css asset paths aren't working.
18 Answers
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