GraphDB export/import or SPARQL to transfer data from a repository to another

Question

I am using GraphDb and have a data update problem : Data in the repository is coming from 2 sources :

• Million of tripples are coming from an external source and updated by a full replace each week
• Thousands of tripples are created by users and are permanent. They use the same ontomogy as the external source and are stored in the same repository so that SPARQL queries can run on both data without any difference. However a simple SPARQL query can retrieve all users tripples.

The problem is about the weeky update of the external source. My first idea was to

• Export users data
• Import with replace the new external dataset
• Reimport users data

Problem : I need to reimport exported data, imports are in RDF format which is not available in export.

Another way (which is about the same):

• Import the weekly update in a new repository
• Copy users data from the 'old' repo to the new one
• Switch the server to the new repo.

Problem : In order to copy users data I need an "INSERT SELECT" SPARQL statement using services which exists in SQL (without services) but not in SPARQL

At last GraphDB Ontorefine should do the work but not efficiently on a weekly base. Another way could be to store users data in a separate repo but SPARQL queries involving sorting could become hard to maintain and slow to run.

I can also export users data in JSON format and programmatically generate RDF/XLM files and send them to the GraphDB API. This is technically possible, I do it in very special cases and this works fine, but not reliable for a big amount of data, slow, and a big developer work.

In short: I am stuck!

Answer 1

See comments, actually this was not a problem but misundertanding the role of graphs in a repository