Question: Which ADO.NET interface is used for connection-oriented
data access? Which class is used for connectionless data access?

Answer: The interface IDataReader is used for connection-oriented
data access. The classes DataSet and DataAdapter are intended
for a connectionless data access.

Question: Assume that several users want to access a
database table at the same time. Would you suggest to use a
connection-oriented or a connectionless access protocol?

Answer: Assumption: several users want to read the data concurrently.
The connectionless architecture is based on the idea of caching the
data and to keep concurrent connections to a database low.