Questions tagged as 'desempenho'

Tagged questions
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Concatenate Strings in Java Loops - StringBuilder or '+'?

Java allows us to concatenate Strings in Java using just the '+' operator String str = "a" + "b" + "c"; It's a simple way to do the job, and much less verbose than using StringBuilder. But in cases of Loops like the one below, which appr...
asked by 27.06.2015 / 14:53
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Is processing time affected by the size of variable names?

I was analyzing some frameworks developed by large companies and noticed a particular uniqueness, their variables and functions usually have small names. Does the size of the variable or function name interfere with processing time? By...
asked by 18.11.2014 / 15:20
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What is unrolling?

In this question I asked about the optimization and performance that the compiler performs. Among the highlighted items, users commented that the compiler does an unrolling loop optimization or unrolling . What is this unrolling ?...
asked by 23.02.2017 / 14:33
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Clustered id rendering speed vs class

Some time ago I saw some tests to render CSS rendering using id to be faster than rendering using class , due to the amount of id is often lower in the document in relation to the number of classes (one of the tests you can check in this ta...
asked by 17.11.2015 / 18:59
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Performance of functions with and without creation of local variables

Despite the simplicity of this question, I could not find an answer for it on the Internet. Is there any structural / performatic difference between the two functions defined below? def F(x): Output = x + 1 return Output def F(x):...
asked by 17.12.2018 / 22:45
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Records with recurring dates filtered by a period

The Problem I am creating a financial system where I need to register a recurring movement, such as a light bill that repeats itself every month. In the system, this type of transaction is treated as a fixed expense / revenue. My table has...
asked by 28.08.2014 / 07:33
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Performative difference of Any () and Count ()

When I need to check whether a collection has elements which of the two methods will be faster, .Count() =! 0 or .Any() ? I've heard that .Count() may be faster in some cases. But by checking the source code , the metho...
asked by 11.08.2015 / 18:33
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What is the best practice to know if a row exists in a SELECT in MySQL?

For example, when we are going to check if a user is already registered in the table, we do not need any data return by the query, just check if the number of rows is greater than 0 ( num_rows > 0 ). In the scripts and frameworks...
asked by 09.07.2015 / 22:36
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What makes join () be so superior compared to other concatenation techniques?

It's common to read that the concatenation method join() is much top other techniques in Python (such as + or += ). Starting from this point, I ask some questions: What does join() do so fast? Should I always...
asked by 17.09.2016 / 00:08
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CDN vs. join JS / CSS

Among the performance recommendations of a web system are: Use CDN (in the case of jQuery, Bootstrap, etc.) Add JS and CSS to decrease the number of requests It turns out that these two rules go against each other. If I use jQuery and B...
asked by 12.06.2014 / 18:24