Greetings!
How about by-passing JDBC/H2 and pushing the data into the MV Store directly?
This way you eliminate any possible bottleneck.
Next was to compare MV Store performance vs. other implementation (e .g. EHCache).
Next next was comparing against Postgres LOAD and or DuckDB read from Parquet. You will need to establish a kind of benchmark first before you can really say what is possible or shall be expected.
I don't know how well MVStore itself performs and where exactly any limitation may come from.
For very most of us, H2/MVStore is just good enough and I assume the most relevant use-case is to have a minimum deploy/maintenance all batteries included Jar DB -- not so much the raw performance.
Cheers
Andreas