Databases
StackOverflow2013
Postsdbo
POHow does having a dynamic variable affect performance?
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POHow does having a dynamic variable affect performance?
    primarykey
    data
    text
    <p>I have a question about the performance of dynamic in C#. I've read dynamic makes the compiler run again, but what does it do? </p> <p>Does it have to recompile the whole method with the dynamic variable used as a parameter or just those lines with dynamic behavior/context? </p> <p>I've noticed that using dynamic variables can slow down a simple for loop by 2 orders of magnitude.</p> <p>Code I have played with:</p> <pre><code>internal class Sum2 { public int intSum; } internal class Sum { public dynamic DynSum; public int intSum; } class Program { private const int ITERATIONS = 1000000; static void Main(string[] args) { var stopwatch = new Stopwatch(); dynamic param = new Object(); DynamicSum(stopwatch); SumInt(stopwatch); SumInt(stopwatch, param); Sum(stopwatch); DynamicSum(stopwatch); SumInt(stopwatch); SumInt(stopwatch, param); Sum(stopwatch); Console.ReadKey(); } private static void Sum(Stopwatch stopwatch) { var sum = 0; stopwatch.Reset(); stopwatch.Start(); for (int i = 0; i &lt; ITERATIONS; i++) { sum += i; } stopwatch.Stop(); Console.WriteLine(string.Format("Elapsed {0}", stopwatch.ElapsedMilliseconds)); } private static void SumInt(Stopwatch stopwatch) { var sum = new Sum(); stopwatch.Reset(); stopwatch.Start(); for (int i = 0; i &lt; ITERATIONS; i++) { sum.intSum += i; } stopwatch.Stop(); Console.WriteLine(string.Format("Class Sum int Elapsed {0}", stopwatch.ElapsedMilliseconds)); } private static void SumInt(Stopwatch stopwatch, dynamic param) { var sum = new Sum2(); stopwatch.Reset(); stopwatch.Start(); for (int i = 0; i &lt; ITERATIONS; i++) { sum.intSum += i; } stopwatch.Stop(); Console.WriteLine(string.Format("Class Sum int Elapsed {0} {1}", stopwatch.ElapsedMilliseconds, param.GetType())); } private static void DynamicSum(Stopwatch stopwatch) { var sum = new Sum(); stopwatch.Reset(); stopwatch.Start(); for (int i = 0; i &lt; ITERATIONS; i++) { sum.DynSum += i; } stopwatch.Stop(); Console.WriteLine(String.Format("Dynamic Sum Elapsed {0}", stopwatch.ElapsedMilliseconds)); } </code></pre>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. USnumaroth
    1. USLukasz Madon
    plurals
    1. PL
      singulars
      1. LTLinked
    2. PL
      singulars
      1. LTLinked
    1. PL
      singulars
      1. LTLinked
    2. PL
      singulars
      1. LTLinked
    3. PL
      singulars
      1. LTLinked
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    2. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. POHow does having a dynamic variable affect performance?
      1. USBastardo
      1. VTFavorite
    2. VO
      singulars
      1. POHow does having a dynamic variable affect performance?
      1. This table or related slice is empty.
      1. VTUpMod
    3. VO
      singulars
      1. POHow does having a dynamic variable affect performance?
      1. This table or related slice is empty.
      1. VTUpMod
    1. CONo, it doesn't run the compiler, that would make it punishing slow on the first pass. Somewhat similar to Reflection but with lots of smarts to keep track of what was done before to minimize the overhead. Google "dynamic language runtime" for more insight. And no, it will never approach the speed of a 'native' loop.
      singulars
      1. POHow does having a dynamic variable affect performance?
      1. USHans Passant
    2. COalso see http://stackoverflow.com/questions/3784317/c-sharp-dynamic-keyword-run-time-penalty
      singulars
      1. POHow does having a dynamic variable affect performance?
      1. USnawfal
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload