Right - it made sense to me to go through the FunctionQuery/ValueSource abstraction to do range filters, as it's a superset of just going off of the FieldCache (it could work with functions, FileFloatSource, and future payload or column-stored fields too).
It would be nice if one could tag a field with info to use ValueSourceRangeFilter for any range queries
As an extra attribute in the schema? e.g.
<field name="xyz" type="integer" indexed="true" stored="true" useValueSourceRangeFilter="true" />
+1 for this. It is easier/cleaner than the local param syntax but I guess we'd need to support both anyway. Solrj does not have API methods to manipulate local params and I think this is a good time to add that support.
I've been meaning to get back to this patch... at a minimum it would need support for all of the field types as well as tests. I think I may even have some local updates since this last patch - I'll have to check.
Can you post your updates?
SOLR-940 (Trie support) is mostly done and I can try to spend some time on this one. Per the 1.4 release discussion, these two are the major features stopping the 1.4 release, though I'm sure we'll find more