lucene-java-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Mathieu Lecarme <math...@garambrogne.net>
Subject Re: Several questions about scoring/sorting + random sorting in an image/related application
Date Fri, 15 Jun 2007 20:14:03 GMT
Walt explain differently what I said.
Lucene can be efficiently use for selecting objects, without sorting  
or scoring anything, then, with id stored in Lucene, you can sort  
yourself with a simple Sortable implementation.
The only limit is that lucene gives you not too much results, with  
your 300 maximal responses, you can play with it easily.

M.
Le 15 juin 07 à 19:07, Walt Stoneburner a écrit :

> Antoine Baudoux writes:
>> I want to be able to give a score to each collection.
>
> Keep in mind, Lucene is computing a score based on quite a number of
> things from how often a term is used in a document, how often it
> appears in the collection of documents, how long the query is, etc.
>
> If your concept of a document's score changes, then I'd be inclined to
> think you're possibly using Lucene in a manner it wasn't designed for.
> That said, I have two thoughts.
>
> THOUGHT ONE
> Use Lucene to locate "records" for you --- what you really are
> interested in getting back _from Lucene_ is the primary key.  Then,
> use this key to do a lookup in your database of the score of the day
> and sort accordingly.  The idea is that Lucene finds, your table
> scores, and because of that you won't need to re-index when something
> changes.
>
> THOUGHT TWO
> Use boosting.  COLLECTION_ONE^5  COLLECTION_THREE^10  etc.  That way
> /if/ the Lucene document appears in the collection, it's score is
> weighted according to your preferences.  You're free to change the
> boosts on a query-by-query basis without having to re-index.
>
>
>> I can use a Very big ... query ... I am afraid that it will be slow.
> Try it.  I think you'll find Lucene is _fast_.  We do some pretty HUGE
> and complicated queries and Lucene just screams.
>
>
>> I can add another field to each document, containing a computed
>> custom score, then i could sort on that field. But i want to avoid
>> this solution at all costs, since it would mean re-indexing all the
>> documents each time the collection scores change.
> Or, use indirection - instead of keeping the score, keep the primary
> key of a score table.  Then in a database, where speed won't be the
> issue, perform the look up.   Honestly, if you're only got 300
> categories, you could keep that simple table in memory using less
> space than a small text file.
>
>
>
>> I would also like to implement random-sorting. ... Is it a good  
>> solution?
>> Is there another way to do it?
>
> This really, really, really feels like you're force fitting Lucene to
> do some business logic piece of a larger application.  May I be so
> bold as to ask what's the _actual_ problem you're trying to solve.
> ("I'm trying to make a hole in a piece of oak" as opposed to "What's
> the best way to sharpen a Phillips screwdriver enough to cut wood?")
>
> Keep in mind that the forum is for Lucene, so parts of your questions
> may be answered outside of the forum.
>
> -wls
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: java-user-unsubscribe@lucene.apache.org
> For additional commands, e-mail: java-user-help@lucene.apache.org
>
>


---------------------------------------------------------------------
To unsubscribe, e-mail: java-user-unsubscribe@lucene.apache.org
For additional commands, e-mail: java-user-help@lucene.apache.org


Mime
View raw message