Hi,

try to look at Compass (http://www.opensymphony.com/compass/). It is built
on top of Lucene but provides additional concepts (transactions is one of
them). You might find this useful depending on your needs.

Regards,
Lukas

On 4/16/07, Erick Erickson <[EMAIL PROTECTED]> wrote:

See below.

On 4/16/07, Moti Nisenson <[EMAIL PROTECTED]> wrote:
>
> Hi,
>
> I was wondering if the addIndexes() method in IndexWriter can be used
for
> updating documents.
>
> Specifically, I'd like to leave my primary index alone during the update
> process. Instead, I want to use a separate index (on a RAMDirectory),
and
> to
> make the updateDocument() calls on it and finally to merge the changes
to
> the primary index. This leads to several questions:
>
> 1) If I make an updateDocument call and the document isn't present in
the
> separate index, will it fail?
> 2) After I merge the indeces, will the documents in the primary index be
> updated (i.e. deleted and then added if existing, otherwise just added)?


No, absolutely not. Lucene identifies documents by document ID. All the
documents in your secondary index will get unique Lucene IDs and
Lucene will NOT remove any documents from your original index.

Lucene has no concept of "document identity" in that you can index
the same document 15 times in a row and Lucene will have 15 entries.


3) If the merge does update the primary index, does it all occur in a
single
> transaction?


"transaction" is really not a Lucene concept. What kind of behavior are
you really looking for here?


Thanks for the help!
>
> Moti
>

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