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Re: faster client pre-1.0: decrease number of files&folders in .svn

From: Branko Čibej <brane_at_xbc.nu>
Date: 2003-02-05 23:38:23 CET

Philip Martin wrote:

>solo turn <soloturn99@yahoo.com> writes:
>
>
>
>>>"Slow down"? To what are you comparing it?
>>>
>>>
>>how it scales with the number of files/folders managed. this is not
>>linear. its minimum 2 times slower (ie 10 times more files managed,
>>20 times more time for "svn st").
>>
>>
>[...]
>
>
>>1. scalability of svn up and svn st:
>> our experience states O(>2), while we believe it
>> should be O(1). you may be partially right, because
>> it is not O(10) like the number of files suggest.
>> but i don't know how many .svn entries are
>> really touched for one file in the repository.
>> --> shows it is non-linear
>>
>>
>
>[Note: If a 10-fold increase in the number of files produces a 20-fold
>increase in runtime that is not O(2). O(2) is quadratic, i.e. double
>the files and quadruple the runtime, ten times the files and a hundred
>times the runtime.]
>

In fact, O(2) is the same as O(1) -- it's constant time, with a
different factor. That solo turn is describing is linear -- O(2n), to be
precise. That's worse in absolute numbers than O(n), but it's still
linear. You'd have quadratic behaviour if a 10x increase in the number
of files gave you a 100x increase in runtime.

Of course, you need more than one data point to estimate the complexity.

-- 
Brane Čibej   <brane_at_xbc.nu>   http://www.xbc.nu/brane/
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Received on Wed Feb 5 23:39:07 2003

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