> We don’t actually have any computer science for DELETE optimized databases.

Depending on how much deleting and when, there might be engineering if not science for this.

If everything is deleted on a schedule, partitioned databases and dropping whole partitions as they expire is a well worn path. Soft delete and compaction also works pretty well if most, but not all things will be deleted. A generational garbage collection kind of thing.

As others said, fixed sized records are easier to manage deletion/replacement with, too.