Behavior differences

The D1 Worker API matches Cloudflare. The storage topology does not.

Compatibility

Topic	Cloudflare	open-compute
Worker API	D1 Worker API	Same: `prepare` / `bind` / `run` / `all` / `first` / `raw` / `exec` / `batch`, sessions, opaque bookmarks, prepared-statement / result / meta
Topology	Hosted D1 with read replicas	Local primary SQLite on the node running ocd
Read replicas	Available	Not provided
Region routing	Available	Not provided
`served_by` geography	Region / colo metadata	Not provided; `served_by_*` is not a geography product
Bookmarks	Cross-replica causality	Local ordering on the same database
`rows_read` / `rows_written`	Billing counters	Local SQLite execution counts
`dump()`	Rejected on hosted non-alpha	Rejected (`D1_DUMP_ERROR`)
REST / `client.v4`	Available	Not provided; use the Worker binding