lucene-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Robert Muir (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (LUCENE-5879) Add auto-prefix terms to block tree terms dict
Date Thu, 02 Oct 2014 13:14:34 GMT

    [ https://issues.apache.org/jira/browse/LUCENE-5879?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14156560#comment-14156560
] 

Robert Muir commented on LUCENE-5879:
-------------------------------------

I think its enough to just add a comment to explain what is happening. 

Its similar to seeing a "BitsetHashMap" or something. people are going to be very confused
unless they have the 'rewind' explanation above.

> Add auto-prefix terms to block tree terms dict
> ----------------------------------------------
>
>                 Key: LUCENE-5879
>                 URL: https://issues.apache.org/jira/browse/LUCENE-5879
>             Project: Lucene - Core
>          Issue Type: New Feature
>          Components: core/codecs
>            Reporter: Michael McCandless
>            Assignee: Michael McCandless
>             Fix For: 5.0, Trunk
>
>         Attachments: LUCENE-5879.patch, LUCENE-5879.patch, LUCENE-5879.patch, LUCENE-5879.patch,
LUCENE-5879.patch, LUCENE-5879.patch, LUCENE-5879.patch, LUCENE-5879.patch, LUCENE-5879.patch
>
>
> This cool idea to generalize numeric/trie fields came from Adrien:
> Today, when we index a numeric field (LongField, etc.) we pre-compute
> (via NumericTokenStream) outside of indexer/codec which prefix terms
> should be indexed.
> But this can be inefficient: you set a static precisionStep, and
> always add those prefix terms regardless of how the terms in the field
> are actually distributed.  Yet typically in real world applications
> the terms have a non-random distribution.
> So, it should be better if instead the terms dict decides where it
> makes sense to insert prefix terms, based on how dense the terms are
> in each region of term space.
> This way we can speed up query time for both term (e.g. infix
> suggester) and numeric ranges, and it should let us use less index
> space and get faster range queries.
>  
> This would also mean that min/maxTerm for a numeric field would now be
> correct, vs today where the externally computed prefix terms are
> placed after the full precision terms, causing hairy code like
> NumericUtils.getMaxInt/Long.  So optos like LUCENE-5860 become
> feasible.
> The terms dict can also do tricks not possible if you must live on top
> of its APIs, e.g. to handle the adversary/over-constrained case when a
> given prefix has too many terms following it but finer prefixes
> have too few (what block tree calls "floor term blocks").



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

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


Mime
View raw message