Still halfway through reading, but what you've made can unlock a lot of use cases.

> I tried SQLite first, but its extension API is limited and write performance with custom storage was painfully slow

For many use cases, write performance does not matter much. Other than the initial import, in many cases we don't change text that fast. But the simpler logistics of having a sqlite database, with the dual (git+SQL) access to text is huge.

That said, for the specific use case I have in mind, postgres is perfectly fine

SQLite is fine right up until you want concurrent writers. Once you need multiple users, cross-host access, or anything that looks like shared infra instead of a local cache, the file-locking model stops being cute and starts setting the rules for the whole design. For collaborative versioning, Postgres makes more sense.

Also SQLite in WAL/WAL2 mode is definitely not amy slower for writing than Postgres either.

sounds great yes. maybe an SQLite version will come in the future

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