- Vector databases and hybrid search?
- Object storage for all the things? Lake houses. Parquet and beyond.
- Continuously materialized views? I'm not sure this one has made the splash but I think about Naiad (Materialize) and Noria (Readyset)
- NewSQL went mostly mainstream (Spanner wasn't included in the last one, but there's been more here with things like CockroachDB, TiDB, etc)
Parquet, Iceberg, and other open formats seem good, but they may hit a complexity wall. There's already some inconsistency between platforms, eg with delete vectors.
Incremental view maintenance interests me as well, and I would like to see it more available on different platforms. It's ironic that people use dbt etc. to test every little edit of their manually coded delta pipelines, but don't look at IVM.
Not only D4M can cater for structured relational data, it's also suitable for non-structured and sparse data in spreadsheet, matrices and graph. It's essentially a generalization of SQL but for all things data.
There's also integration of D4M with SciDB [3].
[1] D4M: Dynamic Distributed Dimensional Data Model:
[2] GraphQL:
[3] D4M: Bringing associative arrays to database engines: