This is great stuff. Datomic for the rest of us. Someone please build an RDF triple store on top of XTDB to get the immutability and easy time travel. I'm considering running both types of databases in parallel just to get these killer features.
TheFreim•7mo ago
> Someone please build an RDF triple store on top of XTDB to get the immutability and easy time travel.
What do the current XTDB across-time queries lack in this regard? I am under the impression that XTDB already supports what you're asking for, from the release notes:
> Full, across-time queries: using SQL:2011's bitemporal primitives and/or 'XTQL' to answer "what did we know, and when?".
> No history/audit tables, triggers required: use it as a regular update-in-place database (you're free to UPDATE and DELETE normally again!), safe in the knowledge that your history is there when you need it.
> Zero-cost, full database snapshots: immediately go back to any point in time without needing to schedule or store periodic snapshots/copies.
delichon•7mo ago
> What do the current XTDB across-time queries lack in this regard?
Inference & reasoning, SPARQL, ontology and linked data integration.
refset•7mo ago
These things should become plausible once the engine supports recursive CTEs and incremental view maintenance. In the meantime you could exploit Arrow interop with other engines (while keeping XTDB as the source of truth) - people have been building in this direction, e.g. using Polars in "Chrontext: Portable SPARQL queries over contextualised time series data in industrial settings" [0]
delichon•7mo ago
TheFreim•7mo ago
What do the current XTDB across-time queries lack in this regard? I am under the impression that XTDB already supports what you're asking for, from the release notes:
> Full, across-time queries: using SQL:2011's bitemporal primitives and/or 'XTQL' to answer "what did we know, and when?".
> No history/audit tables, triggers required: use it as a regular update-in-place database (you're free to UPDATE and DELETE normally again!), safe in the knowledge that your history is there when you need it.
> Zero-cost, full database snapshots: immediately go back to any point in time without needing to schedule or store periodic snapshots/copies.
delichon•7mo ago
Inference & reasoning, SPARQL, ontology and linked data integration.
refset•7mo ago
[0] https://www.sciencedirect.com/science/article/pii/S095741742...