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Is a view faster than a simple query?
...The view is
created with the WITH SCHEMABINDING option.
You can’t always predict what the query optimizer will do. If you’re
using Enterprise Edition, it will automatically consider the unique
clustered index as an option for a query – but if it finds a “better”
index, that will be used. Y...
Syntax behind sorted(key=lambda: …)
...tuple, dict, etc., again determined by the lambda function.
Lets try and predict what happens when I run the following code.
mylist = [(3, 5, 8), (6, 2, 8), ( 2, 9, 4), (6, 8, 5)]
sorted(mylist, key=lambda x: x[1])
My sorted call obviously says, "Please sort this list". The key argument makes t...
Technically, why are processes in Erlang more efficient than OS threads?
...d-specific resources allocated, but that's quite problematic in practice. (Predicting stack requirements is a bit of a black art.) So instead OS threads are particularly designed to be optimal in the case where there are fewer of them (of the order of the number of CPU cores) and where they are doin...
Performance of Arrays vs. Lists
...o big deal (especially if you are on a cpu with a deep pipeline and branch prediction - the norm for most these days) but only your own profiling can tell you if that is an issue.
If you are in parts of your code where you are avoiding heap allocations (good examples are libraries or in hashcode im...
What is the memory consumption of an object in Java?
... at every cache level. All this complexity means you can only very roughly predict RAM consumption.
Measurement methods
You can use Instrumentation.getObjectSize() to obtain an estimate of the storage consumed by an object.
To visualize the actual object layout, footprint, and references, you c...
Detecting an undefined object property
... assign to undefined, but there is no legitimate reason to do so, and it's predictable that doing so may break your code. In C you can #define true false, and in Python you can assign to True and False, but people don't feel the need to design their code in those languages in such a way as to protec...
Why is lazy evaluation useful?
...ry large.
There is, however, a downside to all this: it becomes harder to predict the runtime speed and memory usage of your program. This doesn't mean that lazy programs are slower or take more memory, but it's good to know.
...
Efficiency of premature return in a function
...nd even that may well be undone in many implementations to optimise branch prediction or for some other issue where the platform determines the preferred ordering.
– Steve314
Oct 25 '11 at 9:55
...
How to generate a random string of a fixed length in Go?
... generator, then the attacker could guess the time i'm seeding it with and predict the same output that i'm generating.
– Matej
Oct 22 '15 at 10:33
4
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Unicode equivalents for \w and \b in Java regular expressions?
...R
by replacing them with things that actually work to match Unicode in a predictable and consistent fashion. It’s only an alpha prototype from a single hack session, but it is completely functional.
The short story is that my code rewrites those 14 as follows:
\s => [\u0009-\u000D\u0020\u0...