Rdb - connector - collection
Router - instantiates a specific type of connector
Database connector - implements an interface, so that the router can be connected to the specific type of database.
Defines a Connector trait, that every connector should implement. Contains the common logic, case classes and some default implementations, that may be overwritten by specific connectors, and may use functions implemented in the connectors. (eg. validation)
Contains general test implementations, that may be used in connectors to test connector specific behavior. When applied on a given connector, all the test assertions should be fulfilled assuming correct implementation.
Implements the general database connector trait, and contains bigquery/mssql/mysql/postgresql/redshift specific implementation.