> Today, if I want to store data for my application, I have a choice between good support for rich object types and connections (e.g., Postgres), or good support for history and merging (e.g., Git). There's no one system that provides both.

I like the way you put this. In case anyone's interested in brainstorming I'm dabbling in this problem with a thing called TreeBase (https://jtree.treenotation.org/treeBase/). It's still a toy at this point, but it stores richly typed data as plain text files to leverage git for history and merging and then can use SQLite (or others) for querying and analysis. A very simple database in the wild looks like this: https://github.com/treenotation/jtree/tree/master/treeBase/p...