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Does a UNIQUE constraint automatically create an INDEX on the field(s)?
...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 index can slow down your queries, but you should not worry about them until you actually run into them.
As for testing in...
Relation between CommonJS, AMD and RequireJS?
...er) development given its asynchronous nature and the fact that it has its roots in Dojo's module declaration implementation.
Sources:
RequireJS - Why AMD?
Addy Osmani - Learning JavaScript Design Patterns - Modern Modular JavaScript Design Patterns
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How to configure postgresql for the first time?
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Under Linux PostgresQL is usually configured to allow the root user to login as the postgres superuser postgres from the shell (console or ssh).
$ psql -U postgres
Then you would just create a new database as usual:
CREATE ROLE myuser LOGIN password 'secret';
CREATE DATABASE myd...
Where in a virtualenv does the custom code go?
...which project is used with which virtualenv? Add tiny shell scripts in the root of each folder with the name of the virtualenv you use it with?
– ccpizza
Jul 18 '18 at 10:40
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Why are there two build.gradle files in an Android Studio project?
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<PROJECT_ROOT>\app\build.gradle is specific for app module.
<PROJECT_ROOT>\build.gradle is a "Top-level build file" where you can add configuration options common to all sub-projects/modules.
If you use another module in yo...
Is it expensive to use try-catch blocks even if an exception is never thrown?
...em in your code. Or as Donald Knuth put it: "premature optimization is the root of all evil".
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Tar a directory, but don't store full absolute paths in the archive
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The following command will create a root directory "." and put all the files from the specified directory into it.
tar -cjf site1.tar.bz2 -C /var/www/site1 .
If you want to put all files in root of the tar file, @chinthaka is right. Just cd in to the directo...
What is Domain Driven Design (DDD)? [closed]
... that two customers with the same name are not the same customer
Aggregate roots are objects that own other objects. This is a complex concept and works on the basis that there are some objects that don't make sense unless they have an owner. For example, an 'Order Line' object doesn't make sense ...
Subprocess changing directory
...ediately before executing a subprocess.
For example, to execute ls in the root directory, you either can do
wd = os.getcwd()
os.chdir("/")
subprocess.Popen("ls")
os.chdir(wd)
or simply
subprocess.Popen("ls", cwd="/")
s...
Dealing with “java.lang.OutOfMemoryError: PermGen space” error
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@TimHowland, it can be a permanent fix if the root cause is not classloader leakage, just too many classes/static data in your web app.
– Péter Török
Dec 14 '11 at 8:50
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