Sorting and index norms have space penalties. Sorting on a field creates an array of Java ints, one for every document in the index. Index norms (used for boosting documents and other things) create an array of bytes in the Lucene index files, one for every document in the index.
If you sort on many of your dynamic fields your memory use will explode, and the same with index norms and disk space. On Wed, Dec 30, 2009 at 6:54 AM, A. Steven Anderson <a.steven.ander...@gmail.com> wrote: >> There can be an impact if you are searching against a lot of fields or if >> you are indexing a lot of fields on every document, but for the most part in >> most applications it is negligible. >> > > We index a lot of fields at one time, but we can tolerate the performance > impact at index time. > > It probably can't hurt to be more streamlined, but without knowing more >> about your model, it's hard to say. I've built apps that were totally >> dynamic field based and they worked just fine, but these were more for >> discovery than just pure search. In other words, the user was interacting >> with the system in a reflective model that selected which fields to search >> on. >> > > Our application is as much about discovery as search, so this is good to > know. > > Thanks for the feedback. It was very helpful. > -- > A. Steven Anderson > Independent Consultant > st...@asanderson.com > -- Lance Norskog goks...@gmail.com
