query
Efficient CouchDB time-range queries
CouchDB is a modern key/value-store that has only limited query capabilities (esp. when compared to a typical relational database management system).
All queries are run against materialized views that take only one parameter.
This means that it is very easy to query for documents that were created after a certain point in time, or for ones that were created before, it's not possible to query for documents that have been created between 2 points in time in a single query.
The client application has to issue 2 separate queries and calculate the intersection of a (potentially very large) set of documents itself.
Work with RDF
RDF (Resource Description Framework) is a set of specifications, designed to provide metadata for your data model (general method of modelling information). RDF-Files are stored in a XML like syntax and are used to additional describe the data contained. There also exist an SQL-Query like query language which allows you to extract data from these files. However it would be nice to store these files into a database and easily update or read the data.
