lucene-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Mark Miller (JIRA)" <>
Subject [jira] Updated: (LUCENE-1034) Add new API method to retrieve document field data in a batch
Date Mon, 17 Nov 2008 00:16:45 GMT


Mark Miller updated LUCENE-1034:

    Attachment: LUCENE-1034.patch

I've patched it altogether into one file. I like the idea, but right now, I don't like the
amount of code duplication. Arguably, this could also be moved to the Searcher family, but
could prob live without that. Also still needs a test, but I've lost interest unless the code
dupe can be resolved while maintaining the speed gain.

> Add new API method to retrieve document field data in a batch
> -------------------------------------------------------------
>                 Key: LUCENE-1034
>                 URL:
>             Project: Lucene - Java
>          Issue Type: Improvement
>          Components: Search
>    Affects Versions: 2.2
>         Environment: JDK 1.5.X, Linux & FreeBSD
>            Reporter: Michael Klatt
>            Priority: Minor
>         Attachments:,, LUCENE-1034.patch,,
> I've read in many forums about people who need to retrieve document data for a large
number of search results. In our case, we need to retrieve up to 10,000 results (sometimes
more) from an index of over 100 million documents (our index is about 65 GB).   This can sometimes
take a couple minutes. 
> In one of my attempts to improve performance, I modified the IndexReader interface to
provide a method which looks like:
> public Document[] documents(int[] n, FieldSelector fieldSelector);
> Instead of retrieving document data one at a time, I would request data for many document
numbers in one shot.   The idea was to optimize the seeks on disk so that in the FieldsReader,
the seeks for the indexStream would be done first, then all the seeks in the fieldStream would
be completed.   For a large number of documents, this yielded a 20% speed improvement.  The
improvement was not as much as I was looking for, but I felt that the improvement was significant
enough that I would request changes to the IndexReader interface.
> I'm providing patches for the files that I needed to change for our application.    These
patches are against the 2.2 release.  

This message is automatically generated by JIRA.
You can reply to this email to add a comment to the issue online.

To unsubscribe, e-mail:
For additional commands, e-mail:

View raw message