New methods for Sqoop import with SQL query

Good point.

Technically you could make your own little data type: `sealed trait Target; case class Query(query: String) extends Target; case class Table(tableName: String) extends Target` ... or something like that. Obviously having two methods is a lot simpler.

My only concern about having multiple methods is that it doesn't enforce any consistency across the methods. If you look at `Load`, we had a bunch of load methods, and a bug fix that wasn't applied to one of the methods, and one combination of supposedly independent features that couldn't be expressed (fixed length splitting and generating unique keys). If we had one method with appropriate parameters, we wouldn't have had any of those problems. That's why I combined the load methods in the execution interface.

There's no evidence that we will have the same problems here yet. But it is something to keep an eye on.