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From Chris Lu <chris...@gmail.com>
Subject Re: Lucene database bindings
Date Sat, 17 Sep 2005 15:30:19 GMT
On 9/17/05, markharw00d <markharw00d@yahoo.co.uk> wrote:
> Mag Gam wrote:
> 
> >Does your example store the index in the derby db or somewhere else? I was
> >thinking of indexing a table in a seperate column.
> >
> >
> The software is not an org.apache.lucene.store.Directory implementation
> ie an FSDirectory alternative for persisting Lucene data in a relational
> table.
> Instead, the software demonstrates a way to extend SQL syntax to allow
> Lucene queries to run as in-line functions during the database's
> execution of queries. These hybrid SQL statements can take advantage of
> the usual databases functions for sorting, grouping joins, conditions,
> indexes etc but also use Lucene queries and highlighting functions all
> in the one SQL statement.
> The Lucene indexes used as part of this can be any standard Directory
> implementation (eg RAM, FS).
> 
> The motivation for creating a Lucene/RDBMS hybrid query tool was to
> address issues commonly associated with using just Lucene:
> 1) Sorting on float/date fields and associated memory consumption
> 2) Representing numbers/dates in Lucene (eg having to pad with sufficent
> leading zeros and add
> to index's list of terms)
> 3) Retrieving only certain stored fields from a document (all storage
> can be done in db)
> 4) Issues to do with updating *volatile* data eg price data used in sorts
> 5) Manually coding joins with RDBMS content as custom filters
> 6) Too-many terms exceptions produced by range queries
> 7) Grouping results eg by website
> 8) Boosting docs based on stored content eg date
> 
> These are the sorts of things an RDBMS can help with.
> 
> Cheers
> Mark
> 

Mark,

This is really good stuff! 
I have been thinking about it for a long while.
Thank you for showing us the door!

Basically your lucene_query function will return a true/false in one
of the query predicates for each record.
This will be very useful when other query predicates can filter out a
lot of records.

Is there any hint to give DB to use the lucene_query function last?

Chris Lu
------------------------
Lucene RAD on Any Databases
http://www.dbsight.net

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