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From: Andy Roberts <mail@andy-roberts.net>
To: java-user@lucene.apache.org
Subject: Re: n-gram indexing
Date: Mon, 18 Jul 2005 22:55:46 +0000
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On Monday 18 Jul 2005 21:27, Rajesh Munavalli wrote:
> At what point do I add n-grams? Does the order in which I add n-grams
> affect exact phrase queries later? My questions are
>
> (1) Should I add all the 1-grams followed by 2-grams followed by
> 3-grams..etc sentence by sentence OR
>
> (2) Add all the 1 grams of entire document first before starting 2-grams
> for the entire document?
>
> What is the general accepted notion of adding n-grams of a document?
>
> thanks,
>
> Rajesh

I can't see any real advantage of storing n-grams explicitly. Just index the 
document and use phrase queries. Order is significant with phrase queries if 
I recall correctly, although you can use SpanNearQueries to look for 
unordered ngrams, although I don't know why you would want to!

Perhaps if you explain a little more about what you are trying to achieve more 
generally, we can confirm that you don't need to mess with explicit indexing 
of indexing.

Andy

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