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Subject: Re: Adding another dimension to Lucene searches
From: Mark Harwood <markharw00d@yahoo.co.uk>
In-Reply-To: <4BE51387.7050304@getopt.org>
Date: Sat, 8 May 2010 11:10:45 +0100
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 <4BE51387.7050304@getopt.org>
To: dev@lucene.apache.org

OK, seems like there is some interest.
I'll work on packaging the code/unit tests/demos and make it available.


> matching ids ... but I didn't quite catch from the slides how you =
encode
> the parent-child link... is it just "the next docs are sub-documents
> until the next parent doc"?=20

Yes - using physical proximity avoids any kind of costly look-ups and =
allows efficient streaming/skipTo logic to work as per usual.

The downside is the need to maintain sequences of related docs in the =
same segment - something Lucene currently doesn't make easy with its =
limited control over when segments are flushed. I suspect we'll need =
some discussion on how best to support this.

Another dependency is that Lucene maintains sequencing of documents when =
merging segments together - this is something I think we can rely on =
currently (please correct me if I'm wrong) but I would like to formalise =
this with a Junit test or some other form of commitment which guarantees =
this state of affairs.

Cheers
Mark


On 8 May 2010, at 08:32, Andrzej Bialecki wrote:

> On 2010-05-07 18:25, mark harwood wrote:
>> I have been working on a hierarchical search capability for a while =
now and wanted to see if there was general interest in adopting some of =
the thinking into Lucene.
>>=20
>> The idea needs a little explanation so I've put some slides up here =
to kick things off:
>>=20
>> =
http://www.slideshare.net/MarkHarwood/proposal-for-nested-document-support=
-in-lucene
>=20
> Very cool stuff. If I understand the design correctly, the cost of the
> query is roughly the same as constructing a Filter Query from the =
parent
> query, and then executing the child query with this filter. You =
probably
> use childScorer.skipTo(nextParentId) to avoid actually traversing all
> matching ids ... but I didn't quite catch from the slides how you =
encode
> the parent-child link... is it just "the next docs are sub-documents
> until the next parent doc"? or is it a field in the children that =
points
> to a unique id field of the parent?
>=20
>=20
>=20
> --=20
> Best regards,
> Andrzej Bialecki     <><
> ___. ___ ___ ___ _ _   __________________________________
> [__ || __|__/|__||\/|  Information Retrieval, Semantic Web
> ___|||__||  \|  ||  |  Embedded Unix, System Integration
> http://www.sigram.com  Contact: info at sigram dot com
>=20
>=20
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: dev-unsubscribe@lucene.apache.org
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>=20


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