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Ontop – A Virtual Knowledge Graph System

21 points by hmottestad 6y ago

hmottestad 6y ago
Gives you unified access to all your data spread across all your relational databases. Supports: PostgreSQL, MySQL, SQL server, Oracle and DB2 Allows you to query across all these databases through a unified interface. Supports reasoning to allow for concepts to be modelled differently in each relational database, but be queried through a single model. This means that developers higher up the food chain don't need to know that the old DB2 instance from 2005 that stores experimental turbine data uses a new table per turbine while the new Oracle db uses a single table with column to specify the turbine instead.
mark_l_watson 6y ago
Looks interesting. Years ago, I experimented with the D2RQ project that does something similar. It would be interesting to see a benchmark with something like WikiData or DBPedia converted to a relational database and compared with a RDF store like Virtuoso. Compare query speed, memory use, and index size on disk. Also seeing a comparison of bulk data load times. Anyway, looks like a cool project!
- jerven 6y ago
  The basic idea was done in a nice study by Orri Erling at the time working on virtuoso (now Facebook presto). Which indeed shows the major benefits of recovering a physical schema. http://www.www2015.it/documents/proceedings/proceedings/p864.pdf http://www.www2015.it/documents/proceedings/proceedings/p864...
kendallgclark 6y ago
Gotta say, Stardog's been shipping a virtualization-powered Knowledge Graph platform since 2014...
- jerven 6y ago
  Stardog just has the nicest out of the box experience. Big real differences between an University project and a well supported commercial one.
- hmottestad 6y ago
  I've always wondered if the Stardog implementation is based on the work done by Ontop? I can see from the history of Ontop that they also have releases dating back to 2014.
  - guohuixiao 6y ago
    Indeed, the first implementation of VKG in Stardog v4 in 2014 shipped with Ontop v1.16. Since then, Ontop has evolved and it improved a lot in terms of features and performance.

21 points by hmottestad 6y ago

Gives you unified access to all your data spread across all your relational databases. Supports: PostgreSQL, MySQL, SQL server, Oracle and DB2 Allows you to query across all these databases through a unified interface. Supports reasoning to allow for concepts to be modelled differently in each relational database, but be queried through a single model. This means that developers higher up the food chain don't need to know that the old DB2 instance from 2005 that stores experimental turbine data uses a new table per turbine while the new Oracle db uses a single table with column to specify the turbine instead.

mark_l_watson 6y ago

Looks interesting. Years ago, I experimented with the D2RQ project that does something similar. It would be interesting to see a benchmark with something like WikiData or DBPedia converted to a relational database and compared with a RDF store like Virtuoso. Compare query speed, memory use, and index size on disk. Also seeing a comparison of bulk data load times. Anyway, looks like a cool project!

jerven 6y ago
The basic idea was done in a nice study by Orri Erling at the time working on virtuoso (now Facebook presto). Which indeed shows the major benefits of recovering a physical schema. http://www.www2015.it/documents/proceedings/proceedings/p864.pdf http://www.www2015.it/documents/proceedings/proceedings/p864...

kendallgclark 6y ago

Gotta say, Stardog's been shipping a virtualization-powered Knowledge Graph platform since 2014...

jerven 6y ago
Stardog just has the nicest out of the box experience. Big real differences between an University project and a well supported commercial one.
hmottestad 6y ago
I've always wondered if the Stardog implementation is based on the work done by Ontop? I can see from the history of Ontop that they also have releases dating back to 2014.
- guohuixiao 6y ago
  Indeed, the first implementation of VKG in Stardog v4 in 2014 shipped with Ontop v1.16. Since then, Ontop has evolved and it improved a lot in terms of features and performance.