lucene-java-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Satuluri, Venu_Madhav" <Venu.Madhav.Satul...@deshaw.com>
Subject RE: Lucene Seaches VS. Relational database Queries
Date Thu, 13 Apr 2006 17:22:15 GMT
I am not sure having an index each for each table solves the problem.

(Going by the schema I put in the earlier mail)
You have an index each for tables A, B and C. What is the
lucene-equivalent of the db query 
A.field1 == value1 and B.field2 == value2 and C.field3 == value3.

You cant use MultiSearcher as MultiSearcher executes the same query
across all indexes. Its not going to return any results.

The remaining alternative is to split the query ourselves into 3 parts,
one for each index and then do the AND-operation in our program.
Needless to say, this can get terribly inefficient as query size and
nesting increases.


-----Original Message-----
From: Chris Lu [mailto:chris.lu@gmail.com] 
Sent: Thursday, April 13, 2006 10:21 PM
To: java-user@lucene.apache.org
Subject: Re: Lucene Seaches VS. Relational database Queries


I agree with Jelda.

Lucene is more document-centric. Storing the relationship is not a
good idea. It's better to simply have 2 indexes. Usually when users
search, they can choose which index they want.

Of course, building the indexes will take more time to process-data.

Lucene can not replace relational DB altogether. One reason is Lucene
is more like object-oriented.

Chris Lu
---------------------------------------
Full-Text Lucene Search on Any Databases
http://www.dbsight.net
Faster to Setup than reading marketing materials!

On 4/13/06, Ramana Jelda <ramana.jelda@ciao-group.com> wrote:
> No.. I don't see your solution is performant..
> If each lucene Document corresponds to a row in 'A join B' then Index
> explodes..
> Index size drastically increases.
>
> Why not then creating two indexs A and B.
> And search for A and then from obtained A documents information search
in B.
>
> It seems for me more performant than indexing all 'A join B'
documents.
>
> Any commenters?
>
> Jelda
>
> > -----Original Message-----
> > From: Satuluri, Venu_Madhav [mailto:Venu.Madhav.Satuluri@deshaw.com]
> > Sent: Thursday, April 13, 2006 6:15 PM
> > To: java-user@lucene.apache.org
> > Subject: RE: Lucene Seaches VS. Relational database Queries
> >
> > I think you are asking if we can retain 1:n relationships in lucene.
> >
> > Ok, I'll go out on a limb and give my solution. Say you have
> > a table A and table B with B having multiple rows associated
> > to each row in A.
> > Also your documents are centered around A, i.e. all your
> > queries return some row(s) of A, not B, but you should be
> > able to query on fields in B.
> >
> >
> > In such a case, you need to have multiple documents for each row in
A.
> > To be more specific, if a row in A has 5 corresponding rows
> > in B, then there must be 5 Documents in lucene index
> > corresponding to A. In other words, each lucene Document
> > corresponds to a row in 'A join B'.
> >
> > I am not sure of this scheme. If there are more tables, then
> > this quickly explodes the no. of documents. We'll have as
> > many documents as will be there in {A join B join C join D..
> > }. Plus, we'll need to remove Documents which correspond
> > logically to the same row in A from the Hits.
> >
> > Is there a better way to do this? Or I don't make sense?
> >
> >
> > -----Original Message-----
> > From: Ananth T. Sarathy [mailto:ananth.t.sarathy@gmail.com]
> > Sent: Thursday, April 13, 2006 9:04 PM
> > To: java-user@lucene.apache.org
> > Subject: Re: Lucene Seaches VS. Relational database Queries
> >
> >
> > Ok,
> >  Some of the stuff makes  some sense. I was a little loopy
> > from lack of
> > sleep and some of these solutions don't really cover my concerns....
> >
> >
> > Let's take this movie example. If each member of a production Crew
can
> > have
> > multiple titles that come from a lookup table of Distinct Jobs
> >
> > Titles
> > Assistant Producer
> > Producer
> > Executive Producer
> > Director
> > Director Trainee
> > Stunt Director
> >
> > In the Database there would be a Assocation Table Linking each Crew
> > member
> > the titles they had
> >
> > Crew_Titles
> > Crew_ID   Title
> > 1             Producer
> > 1
> >
> > On 4/12/06, Nadav Har'El <NYH@il.ibm.com> wrote:
> > >
> > > Chris Hostetter <hossman_lucene@fucit.org> wrote on 12/04/2006
> > 01:41:37
> > > AM:
> > > > : them in one field).  One of the problems I see would be with
> > values
> > > that
> > > > : over lap (Example, name where one name is Jason Bateman, and
one
> > is
> > > Jason
> > > > : Bateman Black, and it would be hard to replicate the Discrete
> > Search
> > > for
> > > >
> > > > they way field values are "analyzed" is extremely configurable
--
> > down
> > > to
> > > > the individual field level.  Which means that while you
> > can have an
> > > actor
> > > > field where you can do loose text searching for "bateman" and
get
> > back
> > > > movies staring "Jason Bateman" and "Jason Bateman Black" (and
even
> > Guido
> > > > Batemans" if you use stemming) you can also have another
> > field using
> > a
> > > > KeywordAnalyzer such that a record with teh values "Jason
Bateman"
> > and
> > > > "Jack Black" will only be matched if hte user searches for
"Jason
> > > Bateman"
> > > > or "Jack Black" ... searching for "Bateman Jack" or "Black
Jason"
> > will
> > > not
> > > > work.
> > >
> > > Another possible trick is to have one field, but mark its end with
> > special
> > > tokens, say "^" and "$", so that "Jason Bateman" gets
> > indexed as four
> > > tokens:
> > >      ^ Jason Bateman $
> > > Then, if you want to search for the name Jason Bateman and that
name
> > only,
> > > just search for the phrase "^ Jason Bateman $" - and only this
entry
> > will
> > > match. (you can also continue to search this field normally)
> > >
> > > If you'll think about this, you'll notice that you don't
> > actually need
> > > the beginning-of-field marker ("^") because it's easy to
> > recognize the
> > > beginning of a field because the position there is 0.
Unfortunately,
> > > I don't know how to match position 0 using the standard
QueryParser,
> > > but you can do it with the SpanFirstQuery: for example if we index
> > > Jason Bateman as the three tokens
> > >      Jason Bateman $
> > > then we can search for it using something like
> > >      SpanQuery[] terms = {
> > >            new SpanTermQuery(new Term("actor", "Jason")),
> > >            new SpanTermQuery(new Term("actor", "Bateman")),
> > >            new SpanTermQuery(new Term("actor", "$")) };
> > >      new SpanFirstQuery(new SpanNearQuery(terms, 0, true), 3);
> > > (or something like that... I didn't test this)
> > >
> > >
> > > --
> > > Nadav Har'El
> > >
> > >
> > >
> >
---------------------------------------------------------------------
> > > To unsubscribe, e-mail: java-user-unsubscribe@lucene.apache.org
> > > For additional commands, e-mail: java-user-help@lucene.apache.org
> > >
> > >
> >
> >
> > --
> > Ananth T Sarathy
> >
> >
---------------------------------------------------------------------
> > To unsubscribe, e-mail: java-user-unsubscribe@lucene.apache.org
> > For additional commands, e-mail: java-user-help@lucene.apache.org
> >
> >
>
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: java-user-unsubscribe@lucene.apache.org
> For additional commands, e-mail: java-user-help@lucene.apache.org
>
>

---------------------------------------------------------------------
To unsubscribe, e-mail: java-user-unsubscribe@lucene.apache.org
For additional commands, e-mail: java-user-help@lucene.apache.org


---------------------------------------------------------------------
To unsubscribe, e-mail: java-user-unsubscribe@lucene.apache.org
For additional commands, e-mail: java-user-help@lucene.apache.org


Mime
View raw message