On 4/11/06, Peter Keegan <[EMAIL PROTECTED]> wrote: > Could you explain why an IndexSearcher constructed from multiple readers is > faster than a MultiSearcher constructed from same readers?
The "convergence layer" is a level lower for a MultiReader vs a MultiSearcher. A MultiReader is an IndexReader, and Queries (Scorers) run directly against it since it has efficient TermEnum and TermDocs implementations. A MultiSearcher must do independent searches against subsearchers retrieving the top "n" matches, and maintain an additional priority queue to merge the results to get the global top "n" matches. The implemetation of createWeight is also heavier (heh..) I've never measured the performance difference, and it's probably relatively small for most queries. -Yonik http://incubator.apache.org/solr Solr, The Open Source Lucene Search Server --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
