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From Erik Hatcher <erik.hatc...@gmail.com>
Subject Re: Higher rank for closer matches
Date Wed, 21 Sep 2011 23:46:07 GMT
SpanNearQuery is a different kind of beast than PhraseQuery... it matches when it's nested
SpanQuery's are in proximity.  So it is like multiple PhraseQuery's and checking proximities
of those with one another... or proximity with any other type of SpanQuery.


On Sep 21, 2011, at 11:08 , Em wrote:

> Thanks, Erik.
> If PhraseQuery does not keep track of all matching spans, how does it do
> its work (in comparison to SpanNearQuery)?
> 
> Regards,
> Em
> 
> Am 21.09.2011 19:52, schrieb Erik Hatcher:
>> 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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> 
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