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Difference between a theta join, equijoin and natural join
I'm having trouble understanding relational algebra when it comes to theta joins, equijoins and natural joins. Could someone please help me better understand it? If I use the = sign on a theta join is it exactly the same as just using a natural join?
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Android Studio doesn't see device
The AVD Manager in Android Studio doesn't show my device but adb devices does show it. Am I missing something obvious here?
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Studies on optimal code width?
...racters. I tend to change it to 120 for no reason other than it was the standard at a company I was with a few years back, and no other company has told me to do it differently.
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Is there a library function for Root mean square error (RMSE) in python?
...lso known as MSE, RMD, or RMS. What problem does it solve?
If you understand RMSE: (Root mean squared error), MSE: (Mean Squared Error) RMD (Root mean squared deviation) and RMS: (Root Mean Squared), then asking for a library to calculate this for you is unnecessary over-engineering. All these me...
Asking the user for input until they give a valid response
...put the input method in a while loop. Use continue when you get bad input, and break out of the loop when you're satisfied.
When Your Input Might Raise an Exception
Use try and except to detect when the user enters data that can't be parsed.
while True:
try:
# Note: Python 2.x users s...
When should I use the Visitor Design Pattern? [closed]
...dmit, I just don't get it. I read the wikipedia article for the pattern and I understand its mechanics but I'm still confused as to when I'd use it.
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Is there a good Valgrind substitute for Windows?
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Insure++ takes forever to instrument your code, and forever to execute your code at runtime.
– C Johnson
Aug 9 '10 at 15:12
add a comment
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Script entire database SQL-Server
Is there a way I can get a scripting of all tables, procs, and other objects from a database? I know there's an option to script the database but it only gave me some sort of top level script, certainly not a script to create all tables, procs, udfs, .etc.
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Are global variables in PHP considered bad practice? If so, why?
...l way. I generally have a variable that contains the system configuration, and when I nead to access this variable in a function, I do global $var; .
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How to remove a file from the index in git?
... from the repo, add the relevant files or directories to .gitignore, stage and commit as normal. They'll be gone from the repo but remain untouched in your local tree, and you won't accidentally check them in again.
– Ionoclast Brigham
Dec 7 '14 at 6:27
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