lucene-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Carl Austin (JIRA)" <j...@apache.org>
Subject [jira] Commented: (LUCENE-1690) Morelikethis queries are very slow compared to other search types
Date Mon, 20 Jul 2009 14:45:14 GMT

    [ https://issues.apache.org/jira/browse/LUCENE-1690?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12733234#action_12733234
] 

Carl Austin commented on LUCENE-1690:
-------------------------------------

The cache used for this is a HashMap and this is unbounded.  Perhaps this should be an LRU
cache with a settable maximum number of entries to stop it growing forever if you do a lot
of like this queries on large indexes with many unique terms.
Otherwise nice addition, has sped up my more like this queries a bit.

> Morelikethis queries are very slow compared to other search types
> -----------------------------------------------------------------
>
>                 Key: LUCENE-1690
>                 URL: https://issues.apache.org/jira/browse/LUCENE-1690
>             Project: Lucene - Java
>          Issue Type: Improvement
>          Components: contrib/*
>    Affects Versions: 2.4.1
>            Reporter: Richard Marr
>            Priority: Minor
>         Attachments: LUCENE-1690.patch
>
>   Original Estimate: 2h
>  Remaining Estimate: 2h
>
> The MoreLikeThis object performs term frequency lookups for every query.  From my testing
that's what seems to take up the majority of time for MoreLikeThis searches.  
> For some (I'd venture many) applications it's not necessary for term statistics to be
looked up every time. A fairly naive opt-in caching mechanism tied to the life of the MoreLikeThis
object would allow applications to cache term statistics for the duration that suits them.
> I've got this working in my test code. I'll put together a patch file when I get a minute.
From my testing this can improve performance by a factor of around 10.

-- 
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