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
