Just a note here: Virtuoso is also a full RDMS, so you could probably
keep wikibase db in the same cluster and fix the asynchronicity. That is

Given how the original data is stored (JSON blob inside mysql table) it
would not be very useful. In general, graph data model and Wikitext data
model on top of which Wikidata is built are very, very different, and
expecting same storage to serve both - at least without very major and
deep refactoring of the code on both sides - is not currently very
realistic. And of course moving any of the wiki production databases to
Virtuoso would be a non-starter. Given than original Wikidata database
stays on Mysql - which I think is a reasonable assumption - there would
need to be a data migration pipeline for data to come from Mysql to
whatever is the WDQS NG storage.

Hi Stas,

Data living in an RDBMS engine distinct from Virtuoso is handled via the engines Virtual Database module i.e., you can build powerful RDF Views over ODBC- or JDBC- accessible data using Virtuoso. These view also have the option of being materialized etc..

[1] https://medium.com/virtuoso-blog/conceptual-data-virtualization-for-sql-and-rdf-using-open-standards-24520925c7ce -- Conceptual Data Virtualization using Virtuoso

[2] https://medium.com/virtuoso-blog/generate-relational-tables-to-rdf-relational-graphs-mappings-using-virtuosos-rdb2rdf-wizard-c4b83402599a -- RDF Views generation over SQL RDBMS data sources using the Virtuoso Wizard

-- 
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