A file manipulation command that extracts some of the records from a file is called

How many distinct tuples are there in a relation instance with cardinality 22 ?

Related fields in a database are grouped to form a

Which database level is closest to the users?

The person who interact the database through query language is called

Which of the following operations is used if we are interested only in certain columns of a table ?

Which of the following operations need the participating relations to be union compatible ?

A set of possible data values is called

In the abstraction of a database system the external level is the

A relational database developer refers to a record as