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Postgresql - change the size of a varchar column to lower length
I have a question about the 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 tell which commit a tag points to in Git?
...nfig if you use it a lot:
[alias]
tagcommit = rev-list -n 1
And then call it with:
$ git tagcommit $TAG
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Network tools that simulate slow network connection [closed]
I would like to visually evaluate web pages response time for several Internet connections types (DSL, Cable, T1, dial-up etc.) while my browser and web server are on the same LAN or even on the same machine. Are there any simple network tools or browser plug-ins that slow down network bandwidth to ...
What is the usefulness of `enable_shared_from_this`?
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It enables you to get a valid shared_ptr instance to this, when all you have is this. Without it, you would have no way of getting a shared_ptr to this, unless you already had one as a member. This example from the boost documentation for enable_shared_from_this:
class Y: public enable_s...
How do I create a new GitHub repo from a branch in an existing repo?
...med new-repo,
whose master corresponds to the old repo's new-project, with
all history preserved.
In fact, I found that by using this method, I could create the new repo with a hand-picked selection of branches, renamed as I wanted:
$ git push git@github.com:accountname/new_repo +new-project:mast...
Why create “Implicitly Unwrapped Optionals”, since that implies you know there's a value?
...e two main reasons that one would create an Implicitly Unwrapped Optional. All have to do with defining a variable that will never be accessed when nil because otherwise, the Swift compiler will always force you to explicitly unwrap an Optional.
1. A Constant That Cannot Be Defined During Initializ...
Which Radio button in the group is checked?
... .FirstOrDefault(r => r.Checked);
Note that this requires that all of the radio buttons be directly in the same container (eg, Panel or Form), and that there is only one group in the container. If that is not the case, you could make List<RadioButton>s in your constructor for each...
how to split the ng-repeat data with three columns using bootstrap
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The most reliable and technically correct approach is to transform the data in the controller. Here's a simple chunk function and usage.
function chunk(arr, size) {
var newArr = [];
for (var i=0; i<arr.length; i+=size) {
newArr.push(arr.slice...
Is there an equivalent for the Zip function in Clojure Core or Contrib?
... a collection of zipWith (zipWith3, zipWith4, ...) functions, because they all need to be of a specific type; in particular, the number of input lists they accept needs to be fixed. (The zip, zip2, zip3, ... family can be regarded as a specialisation of the zipWith family for the common use case of ...
Detect application heap size in Android
How do you programmatically detect the application heap size available to an Android app?
9 Answers
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