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https://issues.apache.org/jira/browse/LUCENE-3234?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13054114#comment-13054114
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Robert Muir commented on LUCENE-3234:
-------------------------------------
You can change it if you don't mind. However, I think I agree it would be good
to figure out if there is an n^2 here. This might have some affect on what the
default value should be... ideally there is some way we could fix the n^2.
Is there a way to turn your test case into a benchmark, or do you have a
separate benchmark (the example you mentioned where it blows up really bad).
This could help in looking at what's going on.
> Provide limit on phrase analysis in FastVectorHighlighter
> ---------------------------------------------------------
>
> Key: LUCENE-3234
> URL: https://issues.apache.org/jira/browse/LUCENE-3234
> Project: Lucene - Java
> Issue Type: Improvement
> Reporter: Mike Sokolov
> Attachments: LUCENE-3234.patch
>
>
> With larger documents, FVH can spend a lot of time trying to find the
> best-scoring snippet as it examines every possible phrase formed from
> matching terms in the document. If one is willing to accept
> less-than-perfect scoring by limiting the number of phrases that are
> examined, substantial speedups are possible. This is analogous to the
> Highlighter limit on the number of characters to analyze.
> The patch includes an artifical test case that shows > 1000x speedup. In a
> more normal test environment, with English documents and random queries, I am
> seeing speedups of around 3-10x when setting phraseLimit=1, which has the
> effect of selecting the first possible snippet in the document. Most of our
> sites operate in this way (just show the first snippet), so this would be a
> big win for us.
> With phraseLimit = -1, you get the existing FVH behavior. At larger values of
> phraseLimit, you may not get substantial speedup in the normal case, but you
> do get the benefit of protection against blow-up in pathological cases.
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