-----Oorspronkelijk bericht----- Van: Roy Klein [mailto:[EMAIL PROTECTED] Verzonden: donderdag 14 april 2005 15:40 Aan: java-user@lucene.apache.org Onderwerp: Update performance/indexwriter.delete()?
>>I've got an application that will be doing >>constant updates to an index. >>I've looked into batching those updates, however, >>based on the way the application works, >>the updates can't be batched. You could always batch a single document :) At the moment I have a components that stores documents to write/delete and is called once and a while. This makes it very easy to do batch processing (and also makes it easier to deal with the concurrency problems) >>(Well, I figure with a lot of work, I might be able >>to batch ~10% of the transactions) Another requirement >>of my application is that the index needs to be updated >> synchronously (i.e. a given thread will update a document >>, and then immediately issue a query in which the updated >>document must be in the resulting hits), so keeping a >>"background working copy" of the index and switching >>it out with a live copy doesn't work in this case. This is not possible onless you only process one single document at a time. After the document is writing you have to refresh the readed and find the document. Why do have such a requirement? Are you afraid that a single document is indexed more than once? :) In the platform for Lucene I have writen for all document it is very very Important that the index never contains two (or more)instances of the Same document. This is possible, even with doing batch updates :) >>I started looking at the performance issues involved in updating one >>document at a time, and found that most of the cost is in opening >>and closing readers&writers. That is why batchupdating is invented :) >>So one thing I've been wondering: Why do you need to do >>deletes from an indexreader? Is there some reason why a writer >>couldn't be modified to do both deletes and adds? >>Could someone who is familiar with the design please explain why a reader is >>required? This seems to be a common enough issue that I bet a lot of >>people on this list would benefit from a thorough explanation. ( I just >>ordered the LIA book, if it's explained in there, then my apologies for not having read it before posting here) It is explained in that book ;) Roy --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
