CNIT 272 Final Exam Questions and
Answers
Minimization - -A Primary Key having the fewest number of attributes to
make it unique is called.
- Identifying Relationship - -If the child entity requires the primary key of
the parent entity for its unique identity, then you create ______.
- Non-Identifying Relationship - -If each child record has a unique identifier
of its own, then the relationship is know as a _______.
- Independent Entity - -Entities that have no foreign keys in their pk.
- Dependent Entity - -Entities that have foreign keys in their pk.
- Associative Entity - -An entity that is created as the result of a many-to-
many relationship.
- Update Anomalies - -Abnormalities or problems introduced by insert,
delete, and update (change) actions.
- Index - -An auxiliary file to improve performance.
- First Normal Form - -Previous normal forms (If there are any) and no
recurring attribute values are allowed in an entity (each attribute has one
value per instance)
- Second Normal Form - -An entity that is in any previous normal forms and
every non-primary key attribute is fully functionally dependent on the full
primary key.
EACH non-key attribute carries a fact about the entire key of the entity in
which it resides.
- Third Normal Form - -In 2NF and EACH non-key attribute depends on the
key (the whole key) of that entity and...
NOT on any non-key attribute in the same entity.
NOT on any attribute in another entity.
These dependency issues are called Transitive Dependencies
, - Functional Dependence - -A requirement that a non-key requires the pk.
- Determinant - -A requirement that the pk determines the non-key
attributes.
- Domain - -Representative of all possible valid values. (Datatype, size,
range, default value, etc.)
- Referential Integrity - -Enforces parent-child existence constraints, table
relationships must always be consistent.
- To-Date(c, dfmt) - -Converts the character c in VARCHAR2 datatype to a
date datatype (internal numeric) in the form as specified by dfmt.
(Processing or insertion)
- SYSDATE - -Returns the current date.
- SYSTIMESTAMP - -Returns the full date and time.
- Dual - -The table to refer to when you arnt using a real table. (Usually
used for USERS or DATES)
- To-Char(c, dfmt) - -Converts the date c to a value of VARCHAR2 datatype
in the format specficied by dfmt. (Used to externally display a date)
- NVL(col, sub) - -Substitute a value 'sub' if value in 'col' is null.
- Left Join - -Inner join records plus any primary key (parent) values that do
not have matching foreign key (child) values.
- Right Join - -Inner join records plus any foreign key null values that do not
have matching primary key values from the parent table.
- INTERSECT - -Returns the values that are the same from both tables.
- UNION - -Returns the all values from both tables except for duplicates.
- MINUS - -Returns values from the first table but discluding any values that
were also in the second table.
- DCL (Data Control Language) - -Gives the ability to create users, roles,
object and grant/revoke priveleges.
- DDL (Data Definition Language) - -Creates and alters structure.
CREATE TABLE tablename (column1 datatype(size),)
ALTER TABLE tablename ADD CONSTRAINT/DROP COLUMN/MODIFY/ADD
Answers
Minimization - -A Primary Key having the fewest number of attributes to
make it unique is called.
- Identifying Relationship - -If the child entity requires the primary key of
the parent entity for its unique identity, then you create ______.
- Non-Identifying Relationship - -If each child record has a unique identifier
of its own, then the relationship is know as a _______.
- Independent Entity - -Entities that have no foreign keys in their pk.
- Dependent Entity - -Entities that have foreign keys in their pk.
- Associative Entity - -An entity that is created as the result of a many-to-
many relationship.
- Update Anomalies - -Abnormalities or problems introduced by insert,
delete, and update (change) actions.
- Index - -An auxiliary file to improve performance.
- First Normal Form - -Previous normal forms (If there are any) and no
recurring attribute values are allowed in an entity (each attribute has one
value per instance)
- Second Normal Form - -An entity that is in any previous normal forms and
every non-primary key attribute is fully functionally dependent on the full
primary key.
EACH non-key attribute carries a fact about the entire key of the entity in
which it resides.
- Third Normal Form - -In 2NF and EACH non-key attribute depends on the
key (the whole key) of that entity and...
NOT on any non-key attribute in the same entity.
NOT on any attribute in another entity.
These dependency issues are called Transitive Dependencies
, - Functional Dependence - -A requirement that a non-key requires the pk.
- Determinant - -A requirement that the pk determines the non-key
attributes.
- Domain - -Representative of all possible valid values. (Datatype, size,
range, default value, etc.)
- Referential Integrity - -Enforces parent-child existence constraints, table
relationships must always be consistent.
- To-Date(c, dfmt) - -Converts the character c in VARCHAR2 datatype to a
date datatype (internal numeric) in the form as specified by dfmt.
(Processing or insertion)
- SYSDATE - -Returns the current date.
- SYSTIMESTAMP - -Returns the full date and time.
- Dual - -The table to refer to when you arnt using a real table. (Usually
used for USERS or DATES)
- To-Char(c, dfmt) - -Converts the date c to a value of VARCHAR2 datatype
in the format specficied by dfmt. (Used to externally display a date)
- NVL(col, sub) - -Substitute a value 'sub' if value in 'col' is null.
- Left Join - -Inner join records plus any primary key (parent) values that do
not have matching foreign key (child) values.
- Right Join - -Inner join records plus any foreign key null values that do not
have matching primary key values from the parent table.
- INTERSECT - -Returns the values that are the same from both tables.
- UNION - -Returns the all values from both tables except for duplicates.
- MINUS - -Returns values from the first table but discluding any values that
were also in the second table.
- DCL (Data Control Language) - -Gives the ability to create users, roles,
object and grant/revoke priveleges.
- DDL (Data Definition Language) - -Creates and alters structure.
CREATE TABLE tablename (column1 datatype(size),)
ALTER TABLE tablename ADD CONSTRAINT/DROP COLUMN/MODIFY/ADD
