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From Britske <gbr...@gmail.com>
Subject Re: big discrepancy between elapsedtime and qtime although enableLazyFieldLoading= true
Date Mon, 28 Jul 2008 20:27:38 GMT

Size on disk is 1.84 GB (of which 1.3 GB sits in FDT files if that matters)
Physical RAM is 2 GB with -Xmx800M set to Solr. 


Yonik Seeley wrote:
> 
> That high of a difference is due to the part of the index containing
> these particular stored fields not being in OS cache.  What's the size
> on disk of your index compared to your physical RAM?
> 
> -Yonik
> 
> On Mon, Jul 28, 2008 at 4:10 PM, Britske <gbrits@gmail.com> wrote:
>>
>> Hi all,
>>
>> For some queries I need to return a lot of rows at once (say 100).
>> When performing these queries I notice a big difference between qTime
>> (which
>> is mostly in the 15-30 ms range due to caching) and total time taken to
>> return the response (measured through SolrJ's elapsedTime), which takes
>> between 500-1600 ms.
>>
>> For queries which return less rows the difference becomes less big.
>>
>> I presume (after reading some threads in the past) that this is due to
>> solr
>> constructing and streaming the response (which includes retrieving the
>> stored fields) , which is something that is not calculated in qTime.
>>
>> Documents have a lot of stored fields (more than 10.000), but at any
>> given
>> query a maximum of say 20 are returned (through fl-field ) or used (as
>> part
>> of filtering, faceting, sorting)
>>
>> I would have thought that enabling enableLazyFieldLoading for this
>> situation
>> would mean a lot, since so many stored fields can be skipped, but I
>> notice
>> no real difference in measuring total elapsed time (or qTime for that
>> matter).
>>
>> Am I missing something here? What criteria would need to be met for a
>> field
>> to not be loaded for instance? Should I see a big performance boost in
>> this
>> situation?
>>
>> Thanks,
>> Britske
>> --
>> View this message in context:
>> http://www.nabble.com/big-discrepancy-between-elapsedtime-and-qtime-although-enableLazyFieldLoading%3D-true-tp18698590p18698590.html
>> Sent from the Solr - User mailing list archive at Nabble.com.
>>
>>
> 
> 

-- 
View this message in context: http://www.nabble.com/big-discrepancy-between-elapsedtime-and-qtime-although-enableLazyFieldLoading%3D-true-tp18698590p18698909.html
Sent from the Solr - User mailing list archive at Nabble.com.


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