The class DB must implement an Interface

[KnowledgeGarden]

Right now, DB is hardwired for specific kinds of databases; those which accept DOUBLE as a datatype; PostgreSql does not accept that.

We need to, instead, code for an IDatabase, for which DB is an implementation.
This would allow to write an implementation which can adapt SQL query strings to different providers; for instance, for Postgres, one does a replaceAll on double to integer on all create statements.

Without testing this, I have no clue what the side effects will be, but for now, booting a DB against postgress fails on the first table create which then cascades collapse.