Column Information for BackendSource:
Collects column information for backend.
Currently, this includes:
levels (factor / ordered), but not for the primary key column
col_info(x, ...) # S3 method for data.table col_info(x, primary_key = character(), ...) # S3 method for DataBackend col_info(x, ...)
A backend-like object for which to retrieve column information.
The primary key of the backend.