Other Questions

Question 1

What is a primary key?

Answer 1

One or more columns whose value(s) uniquely identify a row in that table (2.5)

Question 2

What is a foreign key?

Answer 2

One or more columns whose value(s) uniquely identify a row in another table (2.5)

Question 3

What does granularity indicate?

Answer 3

The granularity of a table indicates what level of detail each row represents.
• Higher granularity means more detailed
• Lower granularity means less detailed. The WHERE clause can be used to lower granularity.
(4.35)

Question 4

How can the rule of thumb “Join in the …-to-1 Direction” be summarized?

Answer 4

Join in order of decreasing granularity (6.30)

Question 5

True or False: Join type and table order don’t need to be considered when determining granularity.

Answer 5

False (6.31)

Question 6

True or False: The GROUP BY clause is limited to one column.

Answer 6

False (7.10)

It is NOT limited to one column: it allows for a comma-delimited list of columns.