: > Does Lucene/Solr do, or can it do, any sort of increase on : > relevancy depending on which search result a user picks?
if you have a numeric field in your index, and you want it's value to influence the score, this is easy to achieve using FunctionQuery : As a matter of fact, updating only single field in a document is not : supported in Solr or Lucene last I checked -- you have to post the : whole document (with change) back in. Correct, Ryan has been working on supporting an "update" command to allow individual fields to be modified assume all other fields are stored ... but it's still in the patch stage at the moment. to adress the orriginal question: Lucene at it's core is an inverted index, the nature of which means that to update a document you have to completley replace and readd the old document, and reopen the index for searching -- even with something like Ryan's batch to allow updating documents, it relaly only takes hte burden off your hands to send all the data, Solr still needs to do aall the same work internally to index the whole documents ... so there will allways be some non trivial cost associated with a document update, no matter how minor the update may be. there is also the cost associated with opening a new Searcher on the index to expose the changes you've made ... the more frequently this is done, the more it impacts your ability to cache things, which impacts performance. trade offs have to be made ... typically in situations like this i let the "votes" accumulate and update the all documents that have recieved new votes in batches periodically (as infrequently as neccessary to improve caching yet still meet the needs of my users) -Hoss
