Technically, you should be able to use both 3.0 and 4.0 indexes in the same
app, but a recent inquiry here indicated some unresolved problem. Here's the
official statement from CHANGES.txt for 4.0-BETA:
" - On upgrading to 4.0, if you do not fully reindex your documents,
Lucene will emulate the new flex API on top of the old index,
incurring some performance cost (up to ~10% slowdown, typically).
To prevent this slowdown, use oal.index.IndexUpgrader
to upgrade your indexes to latest file format (LUCENE-3082).
Mixed flex/pre-flex indexes are perfectly fine -- the two
emulation layers (flex API on pre-flex index, and pre-flex API on
flex index) will remap the access as required. So on upgrading to
4.0 you can start indexing new documents into an existing index.
To get optimal performance, use oal.index.IndexUpgrader
to upgrade your indexes to latest file format (LUCENE-3082)."
Bottom line: Write a test and see for yourself.
-- Jack Krupansky
-----Original Message-----
From: Sitowitz, Paul
Sent: Wednesday, August 22, 2012 1:31 PM
To: java-user@lucene.apache.org
Cc: sitow...@gmail.com
Subject: Lucene Index backward compatibility related question
Hello,
I have two products that are using Lucene: The first product creates the
Lucene indexes for some data using Lucene version 3.01. The second product
utilizes the indexes created by the first product for text search purposes
and is also using Lucene 3.01. I understand that the latest version of
Lucene 4.0 has made several performance enhancements of which we would like
to be able to leverage by our second product.
Question: If we upgrade the second product to use Lucene 4.0, will we
still be able to take advantage of search related performance gains while
still using the index created using Lucene 3.01 by our first product? OR,
will we have to "bite the bullet" and upgrade BOTH products to use the
latest version of Lucene?
Thanks in advance for you response.
Sincerely,
Paul Sitowitz
________________________________
P a u l S i t o w i t z
Core Engineering
VeriSign Naming Services
12061 Bluemont Way
Reston, VA 20190
psitow...@verisign.com (email)
703-948-3298 (office)
703-626-3593 (mobile)
This message is intended for the use of the individual or entity to which it
is addressed, and may contain information that is privileged, Confidential
and exempt from disclosure under applicable law. Any unauthorized use,
distribution, or disclosure is strictly prohibited. If you have received
this message in error, please notify sender immediately and destroy/delete
the original transmission
---------------------------------------------------------------------
To unsubscribe, e-mail: java-user-unsubscr...@lucene.apache.org
For additional commands, e-mail: java-user-h...@lucene.apache.org
