Walter, thanks again. Here's some information on the index and search feature.
The index size is close to 25gb, with 20 million documents. it has two collections, one being introduced with 6.6 upgrade. The primary collection carries the bulk of the index, newly formed one being aimed at getting populated going forward. Besides keyword search, the search has a bunch of facets, which are configured to use docvalues. The notable search features being used are highlighter, query elevation, mlt and suggester. The other change from 5.5 was to replace Porter Stemmer with Lemmatizer in the analysis channel. -- Sent from: http://lucene.472066.n3.nabble.com/Solr-User-f472068.html
