[ http://issues.apache.org/jira/browse/LUCENE-509?page=comments#action_12368591 ]
Doug Cutting commented on LUCENE-509: ------------------------------------- You could: (a) add a FieldSelector interface and an IndexWriter method that creates a FieldSelector, then you could pass the FieldSelector instead of the field name to get documents with a subset of the fields; (b) add a getDocuments(int[], String[]) method that reads a set of documents with only the named fields; or (c) you could store fewer fields in your index. > Performance optimization when retrieving a single field from a document > ----------------------------------------------------------------------- > > Key: LUCENE-509 > URL: http://issues.apache.org/jira/browse/LUCENE-509 > Project: Lucene - Java > Type: Improvement > Components: Index > Versions: 1.9, 2.0 > Reporter: Steven Tamm > Attachments: DocField.patch, DocField_2.patch > > If you just want to retrieve a single field from a Document, the only way to > do it is to retrieve all the fields from the Document and then search it. > This patch is an optimization that allows you retrieve a specific field from > a document without instantiating a lot of field and string objects. This > reduces our memory consumption on a per query basis by around around 20% when > a lot of documents are returned. > I've added a lot of comments saying you should only call it if you only ever > need one field. There's also a unit test. -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://issues.apache.org/jira/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
