Loads: As the name suggests, Loads represent the load portion of a given ETL step, which is the step in which data is inserted into the database. In an instance of the Loads object, the user specifies which outputs from the PyBlock are inserted into which columns in the database. Now, each Gen knows which database columns must be populated before it is run (from the Query object) and also which database columns are populated by that Gen (from the Loads object). DBgen needs this information to determine the correct order to run the ETL steps.