[
https://issues.apache.org/jira/browse/LUCENE-4069?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13286712#comment-13286712
]
Robert Muir commented on LUCENE-4069:
-------------------------------------
{quote}
but overlapping choices of fields e.g we want a single Lucene40 to process all
fields but we want Bloom to handle only a subset of these fields.
{quote}
Thats not true: I disagree. Its an implementation detail that Bloom as a
postingsformat wraps another one (thats just the abstract implementation), and
the file formats should not expose this in general for any format.
This is true for a number of reasons: e.g. in the pulsing case the wrapped
writer only gets a subset of the postings: therefore the wrapped writer's files
are "incomplete" and an implementation detail.
its enough here that if you have 5 fields: 2 bloom and 3 not, that we detect
there are only two postings formats in use, regardless of whether you have 2 or
5 actual object instances.
> 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
> Reporter: Mark Harwood
> Priority: Minor
> Fix For: 4.0, 3.6.1
>
> Attachments: BloomFilterPostings40.patch,
> MHBloomFilterOn3.6Branch.patch, PrimaryKey40PerformanceTestSrc.zip
>
>
> 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
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators:
https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira
---------------------------------------------------------------------
To unsubscribe, e-mail: dev-unsubscr...@lucene.apache.org
For additional commands, e-mail: dev-h...@lucene.apache.org
