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Join vs. sub-query
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@user1735921 sure, especially when the query gets so complicated that it does the wrong thing and you spend a day fixing it... there's a balance in between, as usual.
– fabio.sussetto
Nov 30 '17 at 14:29
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Why is transposing a matrix of 512x512 much slower than transposing a matrix of 513x513?
... matrix (64-bit int).
The critical stride would be 2048 bytes, which correspond to 4 rows of the matrix (which is continuous in memory).
Assume we're processing row 28. We're attempting to take the elements of this row and swap them with the elements from column 28. The first 8 elements of the r...
Declaration/definition of variables locations in ObjectiveC?
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I can understand your confusion. Especially since recent updates to Xcode and the new LLVM compiler changed the way ivars and properties can be declared.
Before "modern" Objective-C (in "old" Obj-C 2.0) you didn't have a lot of choices. Instance variables u...
Python assigning multiple variables to same value? list behavior
...ual sense is ok (perhaps with a disclaimer that implementations may vary), esp if the goal is to convey behavior.
– Levon
Aug 5 '15 at 14:47
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Which is faster: Stack allocation or Heap allocation
...single instruction on most architectures, in most cases, e.g. on x86:
sub esp, 0x10
(That moves the stack pointer down by 0x10 bytes and thereby "allocates" those bytes for use by a variable.)
Of course, the stack's size is very, very finite, as you will quickly find out if you overuse stack all...
How to compute the similarity between two text documents?
... between them. Any textbook on information retrieval (IR) covers this. See esp. Introduction to Information Retrieval, which is free and available online.
Computing Pairwise Similarities
TF-IDF (and similar text transformations) are implemented in the Python packages Gensim and scikit-learn. In th...
Why do people say that Ruby is slow? [closed]
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First of all, slower with respect to what? C? Python? Let's get some numbers at the Computer Language Benchmarks Game:
Ruby 1.9 vs. Python3 within the same order of magnitude
Ruby 1.9 vs. PHP within the same order of magnitude
Ruby 1.9 vs. Java 6 ...
Comparison of Android networking libraries: OkHTTP, Retrofit, and Volley [closed]
...er, and the note on the undocumented steez of Volley (got that impression, esp in comparison to the other projects). Definitely helps me get things off the ground.
– Alfie Hanssen
Jun 3 '13 at 21:46
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Why does Windows64 use a different calling convention from all other OSes on x86-64?
...ed Feb 25 '16 at 6:00
Peter CordesPeter Cordes
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What is external linkage and internal linkage?
...n for non-const symbols and static (internal) for const symbols.
// in namespace or global scope
int i; // extern by default
const int ci; // static by default
extern const int eci; // explicitly extern
static int si; // explicitly static
// the same goes for functions (but there are no const func...