tetherless-world / mcs-apps

DARPA Machine Common Sense (MCS) applications for exploring knowledge graphs of common sense, benchmark questions, and question-answering processes
MIT License
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Neo4j stores: add a database schema version node to the database #254

Open gordom6 opened 4 years ago

gordom6 commented 4 years ago

Our database is effectively write-once. We don't really need migrations and such. The middleware should only work with the most current database schema, and refuse to interoperate with an "old" database schema.

The Neo4j store in Scala should: 1) Refuse to write to a non-empty database i.e., there should only ever be one write transaction on a database 2) Check a non-empty database's schema version (node) against a version hard-coded in the Scala. If it's old, print a message and exit.