Hello, I should make one statement unambiguous, as I found some misunderstanding:
Q: "Are Virtual Database, Replication and GeoData not supported at free edition at all or do they have some limitations (for example, connecting to external sources)? As you said for using RDF Views I need to buy license for Virtual Database. And as you also said Virtual Database is not supported at free edition... so is it that correct I can't use RDF Views (for internal relational database) with free edition?" A: "The Virtual Database, Replication, Clustered Server and Geo data features are not supported in the open source (free) Virtuoso product in an form. A commercial license will be required if any of these features are required ..." Comment: In Virtuoso Universal Server, RDF Views can work with both local database tables and remote tables available via virtual schema. Virtuoso Open Source does not support virtual schema so neither RDF Views nor other mechanisms may provide access to remote tables but RDF Views are still fully usable for local tables. In fact, the SPARQL compiler has no idea where the data will be coming from at the run time, from local tables or from remote tables or from views that use some mix inside, it just rewrite the SPARQL to an SQL and let SQL optimizer care about underlaying details. I'd say more. Virtuoso SPARQL supports RDF Views and nothing but :) The configuration of the default Virtuoso RDF storage consists of one default RDF View that consists of one default quad map pattern that tells the SPARQL compiler how to access relational table DB.DBA.RDF_QUAD, its columns and an free-text index. When a developer adds hist first RDF View he adds more quad map patterns at the beginning of the list that is not empty from the very beginning. So it is quite possible to use Virtuoso Open Source for tasks like BI on a mix of relational data with CIA factbook or WordNet or US Census --- as soon as relational data are in local tables. Best Regards, Ivan Mikhailov OpenLink Software http://virtuoso.openlinksw.com
