Which is not a part of the Oracle database

In the context of a relational database, which of the following is NOT a characteristic of a candidate key ?

A surrogate key is:

Which schema in data warehousing uses a central fact table connected to dimension tables?

Which of these is NOT an ensemble method?

What is meant by 'cardinality' in data modeling?

Which OLAP operation allows users to view data at different levels of granularity?

Which of the following best describes a fact constellation schema in a data warehouse?

Fact constellation schema is best described as:

In OLAP, “Slice and Dice” means:

Which of the following best defines the concept of the "Internet of Things" (IoT)?