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From Emmanuel Lecharny <elecha...@gmail.com>
Subject Re: DN storage : Table or Hash ? Some tests...
Date Sun, 02 Mar 2008 22:38:39 GMT
Alan D. Cabrera wrote:
>
> On Feb 25, 2008, at 5:09 AM, Emmanuel Lecharny wrote:
>
>> Hi guys,
>>
>> I did some small tests in order to check if storing DN into a BTree 
>> was slower than using an Hash. Assuming that we have enough memory to 
>> cache data, I found that using a Hash does not bring any kind of 
>> performance boost compared to using a BTree. Worst, it slow down the 
>> wriate operation (twice slower ...).
>>
>> My small test was to store 500 000 DNs, using a 200 000 elements 
>> cache, and searching for 500 000 random DNs from the created structure.
>>
>> Some more insights :
>> - if the cache is not big enough, performances are just incredibly 
>> bad (disk accesses, a hell lot ...)
>> - JDBM might be a little bit too light to support more than a few 
>> hundred of thousands elements.
>
> Very interesting.  Can you check in your stuff into a sandbox?
Well, I was thinking about building a better test, comparing different 
kind of BTrees. I will put it on sandbox later.

But I may also put the tests on the wiki, with the associated code.
>
>
> Regards,
> Alan
>
>


-- 
--
cordialement, regards,
Emmanuel L├ęcharny
www.iktek.com
directory.apache.org



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