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Message-ID: <4AE11057.4080108@gmail.com>
Date: Thu, 22 Oct 2009 22:09:27 -0400
From: Mark Miller <markrmiller@gmail.com>
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To: java-user@lucene.apache.org
Subject: Re: 2.9 per segment searching/caching
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Yes - in many cases, the other wins outweigh the queue transition cost -
in some cases it does not.

But we are talking degradation as you add more segments, not pure speed.
Degradation is worse now in the sort case.

John Wang wrote:
> With many other coding that happened in 2.9, e.g. the PQ api etc., sorting
> is actually faster than 2.4.
> -John
>
> On Thu, Oct 22, 2009 at 5:07 AM, Mark Miller <markrmiller@gmail.com> wrote:
>
>   
>> Bill Au wrote:
>>     
>>> Since Lucene 2.9 has per segment searching/caching, does query
>>>       
>> performance
>>     
>>> degrade less than before (2.9) as more segments are added to the index?
>>> Bill
>>>
>>>
>>>       
>> I think non sorting cases are actually faster now over multiple segments
>> - though you will still see performance degrade pretty signif. over a
>> single segment (I've measured even 5 segments as being 15-20% slower).
>> Doesn't really help the degrade, but should be faster at each point.
>>
>> Sorting is a bit different - you have to convert the p-queue as you go
>> from segment to segment - so the more segments (which also generally
>> means more larger segments), the more conversion you have to do. This
>> didn't appear to be to bad unless you got up to quite a few segments .
>> Worse degradation though.
>>
>> --
>> - Mark
>>
>> http://www.lucidimagination.com
>>
>>
>>
>>
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>>
>>     
>
>   


-- 
- Mark

http://www.lucidimagination.com


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