lucene-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Yonik Seeley (JIRA)" <j...@apache.org>
Subject [jira] Commented: (LUCENE-843) improve how IndexWriter uses RAM to buffer added documents
Date Mon, 30 Apr 2007 14:11:15 GMT

    [ https://issues.apache.org/jira/browse/LUCENE-843?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#action_12492674
] 

Yonik Seeley commented on LUCENE-843:
-------------------------------------

How does this work with pending deletes?
I assume that if autocommit is false, then you need to wait until the end when you get a real
lucene segment to delete the pending terms?

Also, how has the merge policy (or index invariants) of lucene segments changed?
If autocommit is off, then you wait until the end to create a big lucene segment.  This new
segment may be much larger than segments to it's "left".  I suppose the idea of merging rightmost
segments should just be dropped in favor of merging the smallest adjacent segments?  Sorry
if this has already been covered... as I said, I'm trying to follow along at a high level.


> improve how IndexWriter uses RAM to buffer added documents
> ----------------------------------------------------------
>
>                 Key: LUCENE-843
>                 URL: https://issues.apache.org/jira/browse/LUCENE-843
>             Project: Lucene - Java
>          Issue Type: Improvement
>          Components: Index
>    Affects Versions: 2.2
>            Reporter: Michael McCandless
>         Assigned To: Michael McCandless
>            Priority: Minor
>         Attachments: LUCENE-843.patch, LUCENE-843.take2.patch, LUCENE-843.take3.patch,
LUCENE-843.take4.patch, LUCENE-843.take5.patch
>
>
> I'm working on a new class (MultiDocumentWriter) that writes more than
> one document directly into a single Lucene segment, more efficiently
> than the current approach.
> This only affects the creation of an initial segment from added
> documents.  I haven't changed anything after that, eg how segments are
> merged.
> The basic ideas are:
>   * Write stored fields and term vectors directly to disk (don't
>     use up RAM for these).
>   * Gather posting lists & term infos in RAM, but periodically do
>     in-RAM merges.  Once RAM is full, flush buffers to disk (and
>     merge them later when it's time to make a real segment).
>   * Recycle objects/buffers to reduce time/stress in GC.
>   * Other various optimizations.
> Some of these changes are similar to how KinoSearch builds a segment.
> But, I haven't made any changes to Lucene's file format nor added
> requirements for a global fields schema.
> So far the only externally visible change is a new method
> "setRAMBufferSize" in IndexWriter (and setMaxBufferedDocs is
> deprecated) so that it flushes according to RAM usage and not a fixed
> number documents added.

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


Mime
View raw message