As a DBA responsible for a 4TB DWH, WhereScape scares the shit out of me.

Where adding a single column to a table in the Northwind DB during a demo is easy to do, doing the same on a 100GB fact table will block your system for hours. And I'm afraid that using tools like this to be able to be really agile, will allow these things to happen ad hoc, without a DBA even knowing.