refactor: remove R type arg on `DbOption` #1052

Job	Run time
Rust project check (ubuntu-latest)	5m 17s
Rust fmt	22s
Rust project check (macos-latest)	4m 15s
Rust project check (windows-latest)	8m 40s
Rust exmaples	2m 38s
Rust benchmark	0s
	21m 12s

Provide feedback