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What exactly do “u” and “r” string flags do, and what are raw string literals?
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There's not really any "raw string"; there are raw string literals, which are exactly the string literals marked by an 'r' before the opening quote.
A "raw string literal" is a slightly different syntax for a string literal, in which a backslash, \, is taken as meaning "just a backs...
Hibernate, @SequenceGenerator and allocationSize
... know the default behaviour of Hibernate when using @SequenceGenerator - it increases real database sequence by one , multiple this value by 50 (default allocationSize value) - and then uses this value as entity ID.
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Why does string::compare return an int?
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First, the specification is that it will return a value less
than, equal to or greater than 0, not necessarily -1 or 1.
Secondly, return values are rvalues, subject to integral
promotion, so there's no point in returning anything smaller.
In C++ (as in C),...
Developing GUIs in Python: Tkinter vs PyQt [closed]
...erious, especially as things you learn will translate directly to working with Qt in other languages too if you ever need to, and Qt is probably the best cross-platform interface toolkit available right now.
There are only two real (potential) disadvantages:
PyQt is only available under the GPL. ...
Static Block in Java [duplicate]
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It's a static initializer. It's executed when the class is loaded (or initialized, to be precise, but you usually don't notice the difference).
It can be thought of as a "class constructor".
Note that there are also instanc...
what is reverse() in Django
...ead django code sometimes, I see in some templates reverse() . I am not quite sure what this is but it is used together with HttpResponseRedirect. How and when is this reverse() supposed to be used?
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Performance difference for control structures 'for' and 'foreach' in C#
... code snippet will give better performance? The below code segments were written in C#.
9 Answers
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MySQL: multiple tables or one table with many columns?
...time information is one-to-one (each user has one name and password), then it's probably better to have it one table, since it reduces the number of joins the database will need to do to retrieve results. I think some databases have a limit on the number of columns per table, but I wouldn't worry ab...
Is non-blocking I/O really faster than multi-threaded blocking I/O? How?
...antage of nonblocking or asynchronous I/O is that your thread can continue its work in parallel. Of course you can achieve this also using an additional thread. As you stated for best overall (system) performance I guess it would be better to use asynchronous I/O and not multiple threads (so reducin...
How to delete migration files in Rails 3
...:migrate again.
If your application is already on production or staging, it's safer to just write another migration that destroys your table or columns.
Another great reference for migrations is: http://guides.rubyonrails.org/migrations.html
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