Notes:

(3 secs) This is a simplified version of the adapter_class method.

It just takes the adapter scheme given and requires the appropriate adapter file.

In each adapter file, the adapter registers the adapter's database subclass in the ADAPTER_MAP.

Then the adapter class is just looked up in the ADAPTER_MAP and returned.

http://github.com/jeremyevans/sequel/blob/3.10.0/lib/sequel/database.rb#L107