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https://issues.apache.org/jira/browse/LUCENE-1470?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12673912#action_12673912
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Ning Li commented on LUCENE-1470:
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Good stuff!
Is it worth to also have an option to specify the number of precisions to index
a value?
With a large precision step (say 8), a value is indexed in fewer terms (8) but
the number of terms for a range can be large. With a small precision step (say
2), the number of terms for a range is smaller but a value is indexed in more
terms (32). With precision step 2 and number of precisions set to 24, the
number of terms for a range is still quite small but a value is indexed in 24
terms instead of 32. For applications usually query small ranges, the number of
precisions can be further reduced.
We can provide more options to make things more flexible. But we probably want
a balance of flexibility vs. the complexity of user options. Does this number
of precisions look like a good one?
> Add TrieRangeFilter 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-revamp.patch, LUCENE-1470-revamp.patch,
> LUCENE-1470-revamp.patch, LUCENE-1470.patch, LUCENE-1470.patch,
> LUCENE-1470.patch, LUCENE-1470.patch, LUCENE-1470.patch, LUCENE-1470.patch,
> LUCENE-1470.patch, trie.zip, TrieRangeFilter.java, TrieUtils.java,
> TrieUtils.java, TrieUtils.java, TrieUtils.java, 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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