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https://issues.apache.org/jira/browse/LUCENE-4069?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13418393#comment-13418393
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Michael McCandless commented on LUCENE-4069:
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bq. Presumably I am doing the "right thing" in always throwing an exception if
the .blm file is missing?
Definitely! This should be considered a corrupt index.
bq. IF MDW is intended to only delete uncommitted files I'm not sure how we end
up in a scenario where BloomPF is being asked to open the uncommitted segment?
Very strange... IW will sync all files written by the codec, and only once all
files for a given segment are sync'd will it write a segments_N referencing
that segment. Not sure offhand why this file isn't being sync'd... I wonder if
it has to do w/ only opening the file in the close() method (most other PFs
open files well before then). It should be fine to do that ... but it's
something different.
> Segment-level Bloom filters for a 2 x speed up on rare term searches
> --------------------------------------------------------------------
>
> Key: LUCENE-4069
> URL: https://issues.apache.org/jira/browse/LUCENE-4069
> Project: Lucene - Java
> Issue Type: Improvement
> Components: core/index
> Affects Versions: 3.6, 4.0-ALPHA
> Reporter: Mark Harwood
> Priority: Minor
> Fix For: 4.0
>
> Attachments: BloomFilterPostingsBranch4x.patch,
> LUCENE-4069-tryDeleteDocument.patch, LUCENE-4203.patch,
> MHBloomFilterOn3.6Branch.patch, PKLookupUpdatePerfTest.java,
> PKLookupUpdatePerfTest.java, PKLookupUpdatePerfTest.java,
> PKLookupUpdatePerfTest.java, PrimaryKeyPerfTest40.java
>
>
> An addition to each segment which stores a Bloom filter for selected fields
> in order to give fast-fail to term searches, helping avoid wasted disk access.
> Best suited for low-frequency fields e.g. primary keys on big indexes with
> many segments but also speeds up general searching in my tests.
> Overview slideshow here:
> http://www.slideshare.net/MarkHarwood/lucene-bloomfilteredsegments
> Benchmarks based on Wikipedia content here: http://goo.gl/X7QqU
> Patch based on 3.6 codebase attached.
> There are no 3.6 API changes currently - to play just add a field with "_blm"
> on the end of the name to invoke special indexing/querying capability.
> Clearly a new Field or schema declaration(!) would need adding to APIs to
> configure the service properly.
> Also, a patch for Lucene4.0 codebase introducing a new PostingsFormat
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