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Postgresql - change the size of a varchar column to lower length
...e ALTER TABLE command on a really large table (almost 30 millions rows).
One of its columns is a varchar(255) and I would like to resize it to a varchar(40) .
Basically, I would like to change my column by running the following command:
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How to amend a commit without changing commit message (reusing the previous one)?
...lazy, upgrade git and use the built-in command that Shaggle suggests! Plus one for -C option though.
– Dimitris Baltas
Jun 26 '12 at 15:56
4
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What are Scala context and view bounds?
... other words, A should have an implicit conversion to B available, so that one can call B methods on an object of type A. The most common usage of view bounds in the standard library (before Scala 2.8.0, anyway), is with Ordered, like this:
def f[A <% Ordered[A]](a: A, b: A) = if (a < b) a el...
Android: Go back to previous activity
...tp://developer.android.com/reference/android/content/Intent.html
As mentioned in the comments, if the activity is opened with startActivity() then one can close it with finish().
If you wish to use the Up button you can catch that in onOptionsSelected(MenuItem item) method with checking the item I...
Compare object instances for equality by their attributes
...e that in Python 2.5 and onwards, the class must define __eq__(), but only one of __lt__(), __le__(), __gt__(), or __ge__() is needed in addition to that. From that, Python can infer the other methods. See functools for more information.
– kba
Nov 19 '13 at 1:4...
Android Fragment lifecycle over orientation changes
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You're layering your Fragments one on top of the other.
When a config change occurs the old Fragment adds itself to the new Activity when it's recreated. This is a massive pain in the rear most of the time.
You can stop errors occurring by using the same...
kernel stack and user space stack
...rate ] kernel stack used ?
Separation of privileges and security. For one, userspace programs can make their stack(pointer) anything they want, and there is usually no architectural requirement to even have a valid one. The kernel therefore cannot trust the userspace stackpointer to be valid no...
ConcurrentHashMap vs Synchronized HashMap
...re a lock.
Locking the entire collection is a performance overhead. While one thread holds on to the lock, no other thread can use the collection.
ConcurrentHashMap was introduced in JDK 5.
There is no locking at the object level,The locking is at a much finer granularity. For a ConcurrentHashMa...
What are the differences between git branch, fork, fetch, merge, rebase and clone?
I want to understand the difference between a branch, a fork and a clone in Git?
5 Answers
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NuGet auto package restore does not work with MSBuild
...folder.
If you have Nuget 2.7+ installed; it's important to pick one method for > managing Automatic Package Restore in Visual Studio.
Two methods are available:
(Nuget 2.7+): Visual Studio -> Tools -> Package Manager -> Package
Manager Settings -> Enable Auto...