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From Erik Hatcher <erik.hatc...@gmail.com>
Subject Re: Higher rank for closer matches
Date Wed, 21 Sep 2011 17:52:54 GMT
SpanNearQuery does more work than PhraseQuery - it keeps track of all matching spans, whereas
PhraseQuery does not.  Whether the performance difference will be relevant depends on your
environment and data - so it may not be a big deal at all.

	Erik


On Sep 21, 2011, at 10:44 , Em wrote:

> Hi Erik,
> 
> could you explain why PhraseQuery performs better than SpanNearQuery?
> 
> Some time has passed since I read about it, however I think it was
> exactly the other way round.
> 
> Thanks!
> 
> Em
> 
> Am 21.09.2011 15:56, schrieb Erik Hatcher:
>> PhraseQuery suffices for the stated requirement of boosting when query terms are
closer.  A common technique is to incorporate a PhraseQuery with a large slop factor of the
query terms into the query automatically, which implicitly boosts matching documents when
the query terms are closer.  A SpanNearQuery would work too, but a PhraseQuery might be easier
to incorporate and will be faster performing.
>> 
>> 	Erik
>> 
>> On Sep 21, 2011, at 05:31 , Akos Tajti wrote:
>> 
>>> Thanks, I will check SpanNearQuery!
>>> 
>>> Regards,
>>> Ákos
>>> 
>>> 
>>> 
>>> 
>>> On Wed, Sep 21, 2011 at 2:20 PM, Em <mailformailinglists@yahoo.de> wrote:
>>> 
>>>> Àkos,
>>>> 
>>>> have a look at SpanNearQuery. This is what you want.
>>>> If you own the 2nd Edition of Lucene in Action have a look at their
>>>> examples. It illustrates how to combine them with the classical queries.
>>>> 
>>>> Regards,
>>>> Em
>>>> 
>>>> Am 21.09.2011 13:46, schrieb Akos Tajti:
>>>>> Dear List,
>>>>> 
>>>>> for multi term expressions I'd like to add higher rank if the matches
are
>>>>> closer to each other. For example for the search term "like eating" the
>>>>> string "i like eating" comes before "I like some eating".
>>>>> 
>>>>> Is this possible?
>>>>> 
>>>>> Thanks in advance,
>>>>> 
>>>>> Ákos Tajti
>>>>> 
>>>> 
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>>>> 
>> 
>> 
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>> 
> 
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