Hi Dominik, I think most of your questions are answered in the Lucene FAQ and various Lucene articles, so I'll be brief.
----- Original Message ---- From: Dominik Bruhn <[EMAIL PROTECTED]> To: java-user@lucene.apache.org Sent: Saturday, June 10, 2006 6:58:03 PM Subject: Lucene as Search in a BuletinBoard Hy, Im writing a kind of bulletin-board-software in java (servlet+velocity as template framework, mysql5 as backend). As the whole database is in INNODB and this doesn't support Fulltext-Indexes I looked for alternatives and liked the concept of Lucene. But I got serveral questions: 1. Everybody says that Lucene is faster than a MySQL-Fulltext Index. But how comes: MySQL can cache the results in RAM (at least when small) but Lucene has to open the index on the harddisk uppon any search. Why is this so performant. OG: You can open the index only once and reuse IndexReader/Searcher for multiple searches. 2. (Connected to 1): Is there a possibility to tell Lucene to keep the Index in RAM so the access is faster? OG: Yes. Look eda FSDirectory and RAMDirectory. 3. Is the following use of lucene ok? Uppon every posting: After inserting the post into the database-tables I create a IndexWriter, write the new Document and then close the writer again. OG: Yes. Also look at IndexModifier and consider batching delete and add operations when you can. Uppon every editing of a post: I create a IndexReader delete the old Data, close the reader, create a writer, save the document and the close the writer OG: Yes. Also look at IndexModifier and consider batching delete and add operations when you can. Uppon every search: I create a IndexReader and search. OG: You can reuse it. This must be in the FAQ on the Wiki. Isn't it possible to reuse the IndexReader? I thought about creating it one time uppon startup of the servlet and the reuse it. But as I read in the documentation this would result in a locking issue uppon writing. Is this correct? OG: Yes and then no. Yes, you can reuse it. No, no locking issues. 4. I read about the possibility to store the index in a database. When would you consider using this? Is this more performant that a disk-version? OG: No, it is actually slower, people say. Otis --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
