Databases Reference
In-Depth Information
Review Questions
1.
A COMMIT occurs under which three conditions within a transaction?
2.
Under what circumstances can a foreign key column not match the defined
primary key value in the parent table?
3.
True or false: A CHECK constraint cannot check for NULL values.
4.
How are PRIMARY KEY constraints and UNIQUE constraints different? List
two ways.
5.
What are the three conditions that may be specified, either implicitly or
explicitly, on a foreign key column when the primary key column in the par-
ent table is deleted?
6.
Write a CHECK constraint that ensures MAX_SALARY is at least 10,000 more
than MIN_SALARY.
7.
What statement will allow a partial rollback of certain DML statements
within a transaction?
8.
True or false: A NOT NULL constraint can be defined at the table level or at the
column level.
9.
What kind of constraint establishes a parent-child relationship between two
tables via one or more common columns?
10.
If the database crashes while a user session is active, what type of transaction
processing is automatically performed when the database is restarted?
