support sql cursors in Warehouse

[Derek_vanleeuwe]

add support for SQL Cursors, so that we can make better use of metadata / configuration / dynamic sql

[KevinFeit]

I agree with this. Since Warehouse supports primary keys and foreign keys being able to use a cursor would be helpful. For example, looping through INFORMATION_SCHEMA.TABLE_CONSTRAINTS to find all the foreign keys and generate SQL to drop them avoids hard coding.