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https://issues.apache.org/jira/browse/JCR-4057?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15657061#comment-15657061
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Nils Breunese commented on JCR-4057:
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The code could maybe still be changed to not create an anonymous
{{ArrayList<ScoreNode[]>}} of {{offset}} nodes which is not used anywhere,
which would cause the code to use less memory, but I guess that wouldn't be
enough to fix our current performance issue.
> Improve performance of skipping offset nodes for Lucene queries
> ---------------------------------------------------------------
>
> Key: JCR-4057
> URL: https://issues.apache.org/jira/browse/JCR-4057
> Project: Jackrabbit Content Repository
> Issue Type: Improvement
> Components: core
> Affects Versions: 2.10.4
> Reporter: Nils Breunese
> Labels: performance
> Attachments: JCR-4057-test.patch, JCR-4057.patch
>
>
> When doing Lucene-based queries with large offset values like 12000 I see
> pretty bad performance in our system. I have already enabled the
> {{sizeEstimate}} option to improve performance, but still see queries taking
> 6 to 66 seconds.
> I have identified the call to {{collectScoreNodes}} for offset nodes in
> {{org.apache.jackrabbit.core.query.lucene.QueryResultImpl#getResults}} to be
> the cause of this. The {{collectScoreNodes}} method builds an anonymous
> {{ArrayList<ScoreNode[]>}} for the offset nodes, which is not used after
> building it, so it uses memory for nothing, and it also does access checks
> for these nodes which are not returned.
> I have attached a patch to Jackrabbit 2.10.4 which just calls {{skip}} on the
> {{MultiColumnQueryHits result}} and using this patch our query times seem to
> stay under 2 seconds.
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