So what unpredictable performance characteristics do CL & Haskell exhibit, that languages like Java or Erlang do not? Consider Neo4J, Cassandra, CouchDB, Riak,

So what unpredictable performance characteristics do CL & Haskell exhibit, that languages like Java or Erlang do not? Consider Neo4J, Cassandra, CouchDB, Riak, Voldemort, all major players in the current NoSQL world. All use Java & Erlang. Just how much computation does your database need to do, unless it's some special in-memory database like Redis? If you have your data on ordinary disks, you'll spend most of the time waiting for them.