Ayende @ Rahien

Iván Morales commented on The RavenDB indexing process: Optimization–Parallelizing work

Thu, 19 Apr 2012 21:23:46 GMT

Definitely not my day today. I made a mistake when typing the name of the test that ran. These are the corrected results and much more logical;-) [Count>0] 0.22 secs, [Count()>0] 0.86 secs (x3,91 slower then the fastest), [Any()] 4.97 secs (x22,58 slower then the fastest) Thanks Phil

Phil Bolduc commented on The RavenDB indexing process: Optimization–Parallelizing work

Thu, 19 Apr 2012 19:16:55 GMT

@Ivan - I took your souce can and ran my own analysis. I could not corroborate your results. My code is here: http://pastebin.com/QadafRKG One thing I added was to allow the user to pick which order the tests run. I also ran a smaller batch before timing to remove any issues with CPU caches. I ran this on Windows 7 x64 SP1, 16GB RAM, Q9400 @ 2.66GHz, .NET Framework 4 Client Profile Here are my results: D:\>CountAnalysis.exe any-method-property Overhead: 415 Any: 15250 CountMethod: 5877 CountProperty: 304 D:\>CountAnalysis.exe method-property-any Overhead: 413 CountMethod: 5877 CountProperty: 303 Any: 14274 D:\>CountAnalysis.exe property-any-method Overhead: 413 CountProperty: 303 Any: 15391 CountMethod: 5878 D:\>CountAnalysis.exe any-property-method Overhead: 414 CountProperty: 303 Any: 15082 CountMethod: 5893

stu commented on The RavenDB indexing process: Optimization–Parallelizing work

Thu, 19 Apr 2012 17:08:08 GMT

@Phil "Ayende is using the Count property, not the Count() extension method." yeah I noticed that ... afterwards

Iván Morales commented on The RavenDB indexing process: Optimization–Parallelizing work

Thu, 19 Apr 2012 15:50:39 GMT

My test code: http://pastebin.com/awGgJpn9

Phil Bolduc commented on The RavenDB indexing process: Optimization–Parallelizing work

Thu, 19 Apr 2012 14:58:02 GMT

@Iván could you elaborate on the testing? What was the data type, i.e., List, that you used? How many items were in your collection? I think the stackoverflow link that @Simon provided has a good explaination. Using JustDecompile, the Count property on List has the following definition: public int Count { get { return this._size; } } which is returning a private field. The Count() extension method at minimum needs to check if the underlying collection is an ICollection or ICollection. If so, it returns the Count property. It does at minimum one not null check, one cast to ICollection using 'as', and one Count property access. Generally, if the collection is an ICollection the argument of using the Count() extension method or Count property is moot.

Iván Morales commented on The RavenDB indexing process: Optimization–Parallelizing work

Thu, 19 Apr 2012 14:35:02 GMT

Oppps again. Today is not my day :-( Ordered from faster to slower: Count() [Method] -> Count [Property] -> Any() [Method] The fastest way: Count() [Extension Method] Count [Property] is slower than Count() Any() [Extension Method] is much slower then Count property

Iván Morales commented on The RavenDB indexing process: Optimization–Parallelizing work

Thu, 19 Apr 2012 14:29:59 GMT

Phil my previous comment you can results from Count property too My results (without filtering data) ordered from faster to slower: Any() [Method] -> Count [Property] -> Count() [Method]

Phil Bolduc commented on The RavenDB indexing process: Optimization–Parallelizing work

Thu, 19 Apr 2012 14:16:42 GMT

@Ivan/@Stu: Ayende is using the Count property, not the Count() extension method.

Simon commented on The RavenDB indexing process: Optimization–Parallelizing work

Thu, 19 Apr 2012 13:37:34 GMT

Any() definitely can be faster in certain circumstances - as always though, it depends... Good answer here: http://stackoverflow.com/a/305156/54222

Iván Morales commented on The RavenDB indexing process: Optimization–Parallelizing work

Thu, 19 Apr 2012 13:27:33 GMT

Upps, time is in seconds, not milliseconds.

Iván Morales commented on The RavenDB indexing process: Optimization–Parallelizing work

Thu, 19 Apr 2012 13:12:45 GMT

I made some simple tests and these are the results: 0.1461996 ms. [x1.00] Count()> 0 0.6240561 ms. [x4.27] Count> 0 5.0751038 ms. [x34.71] Any() The Count method is the fastest. In other test Count property is 4-6 times slower then Count() and Any() 30-50 times slower

Stu commented on The RavenDB indexing process: Optimization–Parallelizing work

Thu, 19 Apr 2012 11:34:18 GMT

doh ! I thought I was helping as well A quick google came back with http://stackoverflow.com/questions/305092/which-method-performs-better-any-vs-count-0 and http://stackoverflow.com/questions/5741617/listt-any-or-count So I'm guessing FindIndexesFor(doc) returns a List not an IEnumerable Sorry ;-)

Ayende Rahien commented on The RavenDB indexing process: Optimization–Parallelizing work

Thu, 19 Apr 2012 11:29:58 GMT

Stu, Huh? There is no way Any can be faster.

Stu commented on The RavenDB indexing process: Optimization–Parallelizing work

Thu, 19 Apr 2012 11:29:02 GMT

;-) Would you get any more performance if you switch to ".Any()" instead of ".Count > 0" ?