Is it possible in solr to index key-value pairs for a single document, like:
Document ID: 100
2011-05-01,20
2011-08-23,200
2011-08-30,1000
Document ID: 200
2011-04-23,10
2011-04-24,100
and then querying for documents with a specific value aggregation in a specific time range, i.e. "give me documents with sum(value) > 0 between 2011-08-01 and 2011-09-01" would return the document with id 100 in the example data above.
Here is a post from the Solr User Mailing List where a couple of approaches for dealing with fields as key/value pairs are discussed.
1) encode the "id" and the "label" in the field value; facet on it; require clients to know how to decode. This works really well for simple things where the the id=>label mappings don't ever change, and are easy to encode (ie "01234:Chris Hostetter"). This is a horrible approach when id=>label mappings do change with any frequency.
2) have a seperate type of "metadata" document, one per "thing" that you are faceting on containing fields for id and the label (and probably a doc_type field so you can tell it apart from your main docs) then once you've done your main query and gotten the results back facetied on id, you can query for those ids to get the corrisponding labels. this works realy well if the labels ever change (just reindex the corrisponding metadata document) and has the added bonus that you can store additional metadata in each of those docs, and in many use cases for presenting an initial "browse" interface, you can sometimes get away with a cheap search for all metadata docs (or all metadata docs meeting a certain criteria) instead of an expensive facet query across all of your main documents.
