spinergywmy <[EMAIL PROTECTED]> wrote: > > Hi, > > I have ask this question before but may be the question wasn't clear. > > How can I delete particular index that I want to and keep the rest? For > instance, I have been indexed document Id, date, user Id and contents, my > question is does that particular contents will be deleted if I just > specified the document Id, and I used reader.deleteDocument(document Id).
I am not 100% sure what you mean by "delete particular index". Here "index" is mostly used as in "The result of indexing documents with Lucene is an __INDEX__ that can then be searched, updated, etc." But perhaps by index you mean "an __ID__ of a certain document"? Anyhow, assume you created a lucene index and added to it some 1000 documents. You can now delete documents from that index. The remaining index would still be valid and useful but would have less documents that are valid as search results. For instance, if you make 500 calls: reader.deleteDocument(0),reader.deleteDocument(2),...,reader.deleteDocument(998);, your index would now have only 500 remaining documents that are valid as search results. Their (internal) docids would (temporarily) be: 1,3,5,...,999. A few things to notice about this: 1) The fact that these documents were deleted would be: - reflected immediately in searches that use a Searcher opened against the same IndexReader used for these deletions. - reflected in the index Directory only once the deleting IndexReader is closed. - reflected in searches through other IndexSearchers only if they are opened after the deleting IndexReader is closed. 2) The "deleted" documents are still in the index, for some time. They are excluded from search results, since they are marked deleted. When an index segment is merged (either exlicitely as result of call to optimize or implicitely as result of adding a document or closing an index writer), the segment's deleted documnets are actually deleted, and the docids are modified so as to discard the (internal) docids gaps. In the example above, after optimize(), you would have (internal) docid: 0,1,2,..,499. 3) As a consequence of all this, it is usually not the best thing to count on (internal) docids, and so deleting doucments by a term would usually be safer. > > And I have another question is if I do normal cut and paste the document, > how can I delete the index content from one destination and restore to > another destination and the index file must merge. Again I am not sure what you mean here. Is the scenario that you have, say, two Lucene indexes, I1 and I2, and I1 has 100 documents (0.99), and I2 has 100 documents (0..99), and you want to "cut and paste", say, some documents (say, all documents containing the term "MoveMeToTheOtherIndex") from index I1 to I2, and, assume there are 50 documents like this in I1, after that there would be 50 (undeleted) docs left in I1 and 150 docs in I2...? If this is the case Lucene does not supports this and an application would need to implement this by itself - adding the "moved" documents to index I2. Why would you want to do this? > > Thanks > > > regards, > Wooi Meng > -- > View this message in context: > http://www.nabble.com/How-to-delete-partial-index-tf2806204.html#a7829277 --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
