lucene-java-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Marcelo Ochoa" <>
Subject Re: Performance of DbDirectory
Date Wed, 13 Jun 2007 22:19:56 GMT
Hi Simon:
   If you are using Oracle 10g you can get the advantage of using
Lucene inside the Oracle JVM.
   Look at this contribution:
   The most important difference of this implementation in that all
the operation between Lucene to index table data and to store the
inverted index into a BLOB is that everything its made in the same
memory space!! no network roundtrip and data marshalling.
   You can check the difference in term of performance between
FSDirectory and OJVMDirectory simply by running all the Lucene test
suite inside the OJVM or outside.
   My test reports an slightly difference for using the BLOB Api
instead the FS API.
   The other import point in this implementation is the Domain Index
API, it means that all operations are synchronized by the Oracle
RDBMS, so update, insert and delete operations are automatically
handled and synchronized by the Domain Index.
   Best regards, Marcelo.
On 6/13/07, Simon Wistow <> wrote:
> I recently had a thought to do with DbDirectory - specifically would it
> be possible to use something like Oracle's inbuilt replication to have
> mutiple Reader machine being able to read the index with automatic
> partitioning, redundancy and failover?
> Also, what is performance like for DbDirectory compared to FSDirectory?
> And would using DbDirectory and Oracle's backup tools allow for
> snapshots of the index to be taken without having to close the
> IndexWriter and take a physical copy of the index or will that still
> leave unmerged segment files around which will be in an inconsistent
> state at restart (unless Oracle takes an instantaneous snapshot of the
> whole index I suppose).
> Is this a completely loopy idea or mildly sensible?
> Thanks,
> Simon
> ---------------------------------------------------------------------
> To unsubscribe, e-mail:
> For additional commands, e-mail:

Marcelo F. Ochoa
Do you Know DBPrism? Look @ DB Prism's Web Site
More info?
Chapter 17 of the book "Programming the Oracle Database using Java &
Web Services"
Chapter 21 of the book "Professional XML Databases" - Wrox Press
Chapter 8 of the book "Oracle & Open Source" - O'Reilly

To unsubscribe, e-mail:
For additional commands, e-mail:

View raw message