title: index size impact on search speed (to store or not to store)
body: <p>right now, we are using Solr as an fulltext index, where all fields of the documents are indexed but not stored.
  There are some million documents, index-size is 50 GB. Average query-time is around 100ms.</p>
  
  <p>To use features like Highlighting, we are thinking about to: additional store text. But, that could double the size of the index-files.</p>
  
  <p>I know there is absolutely no (linear) relation between index size and query time. Rising the documents on factor 10 results in nearly no difference of query time.</p>
  
  <p>But at all, the system (Solr/Lucene/Linux/...) has to handle more informations - the index files (for example) are based on much more I-nodes, and so on.</p>
  
  <p>So I'm sure, there is an impact on query time in relation to the index-size. (But: is this noticeably?)</p>
  
  <p>1st:
  Do you think, I'm right?
  Did you have any experiences on index-size and search speed in relation to with/without stored text?
  Is it smart and reasonable to blow up the index by storing the documents?</p>
  
  <p>2nd:
  Do you know, how Solr/Lucene handled stored text? Maybe in separate files? (So that there is no impact for simples searches, where no stored text is needed!?)</p>
  
  <p>Thank you.</p>