1. You need an ITypeResolver instance in order to retrieve the correct CLR Type based on a given SQL Type. In order to achieve this goal you need to add the following code snippet to your application:
// the code snippet is based on the provided sample in the previous answer
MetadataContainer container = reader.GetSchema(readParameters);
ITypeResolver resolver = reader.GetTypeResolver(container);
Type clrType = resolver.MetaColumnToClrType(column);
2. The Telerik.OpenAccess.Metadata.Backend
enumeration declares the names of all supported backends in OpenAccess ORM. You could retrieve a list with backend names based on this enumeration type.
3. You need to be aware of the underlying database only when you want to execute operations against it - schema reader, query execution, schema migration, ect.
4. I am afraid that currently we do not provide such documentation.
is not on our to-do list. If this is important to you, please feel free to add an entry to our Ideas & Feedback portal
the Telerik team
Q3'12 SP1 of OpenAccess ORM packs Multi-Table Entities mapping support. Check it out.