[
https://issues.apache.org/jira/browse/LUCENE-4069?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13283574#comment-13283574
]
Michael McCandless commented on LUCENE-4069:
--------------------------------------------
bq. I see a 35% improvement over standard Codecs on random lookups on a warmed
index.
Impressive! This is for primary key lookups?
It looks like the primary keys are GUID-like right? (Ie randomly generated).
I wonder if they had some structure instead (eg '%09d' % (id++)) how the
results would look...
bq. I also notice that the PulsingCodec is no longer faster than standard Codec
- is this news to people as I thought it was supposed to be the way forward?
That's baffling to me: it should only save seeks vs Lucene40 codec, so on a
cold index you should see substantial gains, and on a warm index I'd still
expect some gains. Not sure what's up...
bq. I can open a seperate JIRA issue for this 4.0 version of the code if that
makes more sense.
I think it's fine to do it here? Really 3.6.x is only for bug fixes now ... so
I think we should commit this to trunk.
I wonder if you can wrap any other PostingsFormat (ie instead of hard-coding to
Lucene40PostingsFormat)? This way users can wrap any PF they have w/ the bloom
filter...
Can you use FixedBitSet instead of OpenBitSet? Or is there a reason to use
OpenBitSet here...?
> 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
> Reporter: Mark Harwood
> Priority: Minor
> Fix For: 3.6.1
>
> Attachments: BloomFilterCodec40.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 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.
--
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
