lucene-java-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Daan de Wit" <d.de....@wis.nl>
Subject RE: Is it possible to get only one Field from a Document?
Date Wed, 11 Jun 2008 11:43:58 GMT
This is possible, you need to provider a FieldSelector to IndexReader#document(docId, selector).
This won't work with Hits though, because Hits does not expose the document number, so you
need to roll your own solution using TopDocs or HitCollector, for information see the discussion
in this issue: https://issues.apache.org/jira/browse/LUCENE-1290

Kind regards,
Daan de Wit

-----Original Message-----
From: Marcelo Schneider [mailto:marcelo.schneider@digitro.com.br] 
Sent: Wednesday, June 11, 2008 13:29
To: java-user@lucene.apache.org
Subject: Is it possible to get only one Field from a Document?

I have a environment where we have indexed a DB with about 6mil entries 
with Lucene, and each row has 25 columns. 20 cols have integer codes 
used as filters (indexed/unstored), and the other 5 have (very) large 
texts (also indexed/unstored). Currently the search I'm doing is like this:

Hits hits = searcher.search(query);
for (int i = 0; i < this.hits.length(); i++) {
    Document doc = this.hits.doc(i);
    String s = doc.get("fieldWanted");
     // does everything with the result, etc
}

We are trying to reduce memory usage, however. Is it possible to return 
a Document object with just the Fields I really need? In the example, 
each Document have 25 fields, and I just need one... would this 
theoretically make any difference?




-- 

Marcelo Frantz Schneider
SIC - TCO - Tecnologia em Engenharia do Conhecimento
DÍGITRO TECNOLOGIA
E-mail: marcelo.schneider@digitro.com.br
Site: www.digitro.com


-- 
Esta mensagem foi verificada pelo sistema de antivírus da Dígitro e
acredita-se estar livre de perigo.


---------------------------------------------------------------------
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