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From "Uwe Schindler (JIRA)" <j...@apache.org>
Subject [jira] Commented: (LUCENE-1470) Add TrieRangeQuery to contrib
Date Sat, 07 Feb 2009 18:30:59 GMT

    [ https://issues.apache.org/jira/browse/LUCENE-1470?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12671502#action_12671502
] 

Uwe Schindler commented on LUCENE-1470:
---------------------------------------

Adding that as comment:

> On Sat, Feb 7, 2009 at 12:29 PM, Uwe Schindler <uwe@thetaphi.de> wrote:
> > This is only a minimal optimization, suitable for very large indexes.
> The
> > problem is: if you have many terms in highest precission (a lot of
> different
> > double values), seeking is more costly if you jump from higher to lower
> > precisions.
> 
> That's my point... in very large indexes this should not result in any
> difference at all on average because the terms would be no where near
> each other.

OK.

I prepare a new TrieRangeFilter implementation, just taking the String[] fieldnames and the
sortableLong and the precisionStep.

And I think, you are right. One could completely remove the "storing" API. If one wants to
add stored fields, he could use NumberUtils and do this separately. For TrieRangeFilter it
is not neded.

> As an example: in a very big index, one wants to independently collect
> all documents that match "apple" and all documents that match "zebra",
> which term you seek to first should not matter.

OK, I agree :)


> 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: Uwe Schindler
>             Fix For: 2.9
>
>         Attachments: fixbuild-LUCENE-1470.patch, fixbuild-LUCENE-1470.patch, LUCENE-1470-readme.patch,
LUCENE-1470.patch, LUCENE-1470.patch, LUCENE-1470.patch, LUCENE-1470.patch, LUCENE-1470.patch,
LUCENE-1470.patch, LUCENE-1470.patch, TrieUtils.java
>
>
> 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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