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Arrays, heap and stack and value types
...ove code, is new int[100] generating the array on the heap? From what I've read on CLR via c#, the answer is yes. But what I can't understand, is what happens to the actual int's inside the array. As they are value types, I'd guess they'd have to be boxed, as I can, for example, pass myIntegers to o...
What is the difference between partitioning and bucketing a table in Hive ?
...You'll have 50 buckets with data, and 206 buckets with no data.
Someone already mentioned how partitions can dramatically cut the amount of data you're querying. So in my example table, if you want to query only from a certain date forward, the partitioning by year/month/day is going to dramaticall...
Data access object (DAO) in Java
...d to access data from every source (DBMS, XML and so on). I suggest you to read some examples, like this one:
DAO Example
Please note that there are different ways to implements the original DAO Pattern, and there are many frameworks that can simplify your work. For example, the ORM (Object Relati...
Why must we define both == and != in C#?
... C#:
Many developers wish there was a language that was easy to write, read, and maintain like Visual Basic, but that still provided the power and flexibility of C++.
Yes the design goal for C# was to give nearly the same amount of power as C++, sacrificing only a little for conveniences like ...
Bash continuation lines
...ripleee suggested). But a here document becomes a stdin, so it needs to be read back in, I went with the below approach:
message=$(
tr "\n" " " <<- END
This is a
long message
END
)
somecommand --message="$message" args
This has the advantage that $message can be used exa...
How does `scp` differ from `rsync`?
...ajor difference between these tools is how they copy files.
scp basically reads the source file and writes it to the destination. It performs a plain linear copy, locally, or over a network.
rsync also copies files locally or over a network. But it employs a special delta transfer algorithm and a ...
Select first row in each GROUP BY group?
...rchases (customer, total DESC, id);
May be too specialized. But use it if read performance for the particular query is crucial. If you have DESC NULLS LAST in the query, use the same in the index so that sort order matches and the index is applicable.
Effectiveness / Performance optimization
Weigh ...
Django dynamic model fields
... django-dynamo idea further. The project is still undocumented but you can read the code at https://github.com/charettes/django-mutant.
Actually FK and M2M fields (see contrib.related) also work and it's even possible to define wrapper for your own custom fields.
There's also support for model opt...
What is Mocking?
...le in-memory structure for storing records. The object under test can then read and write records to the database stub to allow it to execute the test. This could test some behavior of the object not related to the database and the database stub would be included just to let the test run.
If you ins...
Column order manipulation using col-lg-push and col-lg-pull in Twitter Bootstrap 3
I'm now reading documentation on Twitter Bootstrap 3, and tried to follow column ordering as shown in this page but hit the wall. I don't understand why such a code works nor how to correctly specify the setting. What I want to show is one grid, which is consisted of length 5, and the other leng...