Yes, you're right, my mistake. (So only the stateless/stateful more/less simple consideration remains).
"jacky" <[EMAIL PROTECTED]> wrote on 05/09/2006 23:57:44: > doron, Thanks! > But in lucene api: For performance reasons it is recommended to > open only one > IndexSearcher and use it for all of your searches. > http://lucene.apache. > org/java/docs/api/org/apache/lucene/search/IndexSearcher.html > > That is a searcher will remain open unless you update the index. > So,that will not > cost much memory and you can get the results whenever you want, and > the performance > will be better, right? (Don't think about state of users in webapp > for a while) > > Best Regards. > jacky > > ----- Original Message ----- > From: "Doron Cohen" <[EMAIL PROTECTED]> > To: <java-user@lucene.apache.org> > Sent: Wednesday, September 06, 2006 2:06 PM > Subject: Re: Keep hits in results > > > > Hits is not really a simple container - it references a certain searcher - > > that same searcher that was used to find these hits. When a request for a > > result document is made, the Hits object delegates this request to the > > searcher. So in order to "page through" the results using an existing Hits > > object, that searcher has to remain open. This has a cost - in terms of > > memory, etc. But LIA describes an additional penalty of this approach - for > > a Web search application, keeping the Hits object alive for the case that > > the user would like to see the next "page of results", means "maintaining a > > user state on the server", While this is possible, it is a more complicated > > server side logic to implement, much more complicated than the stateless > > approach where a query is resubmitted for each new page of results. I think > > what LIA really means is - here and also in other cases - let's not > > complicate things (e.g. statefull solution) unless this is really necessary > > (e.g. performance wise in a certain application it is out of the question > > to resubmit a query for every page, etc.) > > > > Hope this helps, > > Doron > > > > "jacky" <[EMAIL PROTECTED]> wrote on 05/09/2006 21:56:53: > > > > > hi, > > > The following words are quoted from "lucene in action": > > > "There are a couple of implementation approaches: > > > 1. Keep the original Hits and IndexSearcher instances available while > > the > > > user is navigating the search results. > > > 2. Requery each time the user navigates to a new page. > > > It turns out that requerying is most often the best solution. > > > Requerying eliminates > > > the need to store per-user state. In a web application, staying stateless > > (no > > > HTTP session) is often desirable. Requerying at first glance seems > > awaste, but > > > Lucene’s blazing speed more than compensates. " > > > > > > I am confused about this paragraph. Since Hits is just a simple > > > container of pointers > > > to ranked search results, it doesn't load from the index all > > > documents that match a query, > > > but only a small portion of them at a time. If we requery, we will > > > get a new hits, why not > > > just keeping the orginal Hits which will not waste much memory. > > > > > > > > > > > > Best Regards. > > > jacky > > >
