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Difference between Hive internal tables and external tables?
...use lists of partitions without going to the file-system and finding them, etc). These sorts of things are the 'metadata'.
When you drop an internal table, it drops the data, and it also drops the metadata.
When you drop an external table, it only drops the meta data. That means hive is ignorant o...
PDOException “could not find driver”
... get it working, you will need to restart your web-server:
Apache: sudo /etc/init.d/apache2 restart
Nginx: sudo /etc/init.d/nginx restart
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Where is the documentation for the values() method of Enum?
...od that returns an
array containing all of the values of the enum in the order they are
declared. This method is commonly used in combination with the
for-each construct to iterate over the values of an enum type.
Enum.valueOf class(The special implicit values method is mentioned in descrip...
How to trigger XDebug profiler for a command line PHP script?
...working on Ubuntu/Netbeans by:
copying the xdebug config lines from the /etc/php5/apache2/php.ini file into /etc/php5/cli/php.ini
setting an environment variable with the name of the debug session (you can get this from the query string in the url of the page netbeans launches when you start debug...
Why is quicksort better than mergesort?
...t into a BTREE datastructure for the index. (BTREEs are naturally kept in order, so you can load one from a sorted dataset with few seeks to disk.)
There have been a number of occasions where understanding how to avoid disk seeks has let me make data processing jobs take hours rather than days or ...
Check if multiple strings exist in another string
... if x in str]
If you want to get all non-duplicate matches (disregarding order):
matches = {x for x in a if x in str}
If you want to get all non-duplicate matches in the right order:
matches = []
for x in a:
if x in str and x not in matches:
matches.append(x)
...
What is the difference between Swing and AWT?
...stem window and then paints pictures of buttons, labels, text, checkboxes, etc., into that window and responds to all of your mouse-clicks, key entries, etc., deciding for itself what to do instead of letting the operating system handle it. Thus Swing is 100% portable and is the same across platform...
How to add MVC5 to Visual Studio 2013?
...erent ASP.Net features.
You must select .NET Framework 4.5 (or higher) in order to see the ASP.NET Web Application template (For ASP.NET One).
So just select Visual C# > Web > ASP.NET Web Application, then select the MVC checkbox in the next step.
Note: Make sure not to select the C# > We...
Migration: Cannot add foreign key constraint
...ed as a primary key in it's original table. Migrations get executed in the order they were created as indicated by the file name generated after running migrate:make. E.g. 2014_05_10_165709_create_student_table.php.
The solution was to rename the file with the foreign key to an earlier time than th...
How to use Global Variables in C#?
...me namespace):
String code = Globals.CODE_PREFIX + value.ToString();
In order to deal with different namespaces, you can either:
declare the Globals class without including it into a specific namespace (so that it will be placed in the global application namespace);
insert the proper using dire...