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From "Mark Harwood (JIRA)" <j...@apache.org>
Subject [jira] Commented: (LUCENE-1470) Add TrieRangeQuery to contrib
Date Thu, 27 Nov 2008 21:20:44 GMT

    [ https://issues.apache.org/jira/browse/LUCENE-1470?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12651418#action_12651418
] 

Mark Harwood commented on LUCENE-1470:
--------------------------------------

A note of caution - I noticed when moving from Lucene 2.3 to 2.4 that my similar scheme for
encoding information meant that I couldn't encode information using byte arrays using bytes
with values > 216.
The changes (I think in Lucene-510) introduced some code that modified the way the bytes were
written/read and corrupted my encoding.

Not sure if your proposed approach is prone to this or if anyone can cast further light on
these encoding issues.

Good to see this making its way into Lucene, Uwe.

> Add TrieRangeQuery to contrib
> -----------------------------
>
>                 Key: LUCENE-1470
>                 URL: https://issues.apache.org/jira/browse/LUCENE-1470
>             Project: Lucene - Java
>          Issue Type: New Feature
>          Components: contrib/*
>    Affects Versions: 2.4
>            Reporter: Uwe Schindler
>            Assignee: Michael McCandless
>         Attachments: LUCENE-1470.patch, LUCENE-1470.patch, LUCENE-1470.patch, LUCENE-1470.patch
>
>
> According to the thread in java-dev (http://www.gossamer-threads.com/lists/lucene/java-dev/67807
and http://www.gossamer-threads.com/lists/lucene/java-dev/67839), I want to include my fast
numerical range query implementation into lucene contrib-queries.
> I implemented (based on RangeFilter) another approach for faster
> RangeQueries, based on longs stored in index in a special format.
> The idea behind this is to store the longs in different precision in index
> and partition the query range in such a way, that the outer boundaries are
> search using terms from the highest precision, but the center of the search
> Range with lower precision. The implementation stores the longs in 8
> different precisions (using a class called TrieUtils). It also has support
> for Doubles, using the IEEE 754 floating-point "double format" bit layout
> with some bit mappings to make them binary sortable. The approach is used in
> rather big indexes, query times are even on low performance desktop
> computers <<100 ms (!) for very big ranges on indexes with 500000 docs.
> I called this RangeQuery variant and format "TrieRangeRange" query because
> the idea looks like the well-known Trie structures (but it is not identical
> to real tries, but algorithms are related to it).

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