DB Section 9 Quiz

The Oracle Database can implement a many to many relationship. You simply create two foreign keys between the two tables. True or False?

-False

A barrred Relationship will result in a Foreign Key column that also is part of: -The Primary Key -The Column Name -The Check Constraint -The Table Name

-The Primary Key

In a physical data model, an attribute becomes a _____________. -Constraint -Table -Foreign Key -Column

-Column

Identify all of the correct statements that complete this sentence: A primary key is: (Choose Three)(Choose all correct answers) -Only one column that cannot be null -A set of columns and keys in a single table that uniquely identifies each row in a single table -A single column that uniquely identifies each row in a table -A set of columns that uniquely identifies each row in a table

-A set of columns and keys in a single table that uniquely identifies each row in a single table -A single column that uniquely identifies each row in a table -A set of columns that uniquely identifies each row in a table

Which of the following is a valid reason for considering a Subtype Implementation? -The common access paths for the supertypes are different. -The resulting table will reside in a single database and be used by just ONE user. -Business functionality, business rules, access paths, and frequency of access are all very different between the subtypes. -Most of the relationships are at the supertype level.

-Business functionality, business rules, access paths, and frequency of access are all very different between the subtypes.

The explanation below is an example of which constraint type? A column must contain only values consistent with the defined data format of the column -Column integrity -User-defined integrity -Referential integrity -Entity integrity

-Column integrity

Column integrity refers to: -Columns always containing positive numbers -Columns always containing values consistent with the defined data format -Columns always containing text data less than 255 characters -Columns always having values

-Columns always containing values consistent with the defined data format

When an Arc is transformed to the physical model every relationship in the Arc becomes a mandatory Foreign Key. True or False?

-False

When mapping supertypes, relationships at the supertype level transform as usual. Relationships at subtype level are implemented as foreign keys, but the foreign key columns all become mandatory. True or False?

-False

To resolve a many to many relationship in a physical model you create a(n) ___________________? -Unique key constraints -Intersection entity -Intersection table -Two tables with Foreign key constraints between them

-Intersection table

When translating an arc relationship to a physical design, you must turn the arc relationships into foreign keys. What additional step must you take with the created foreign keys to ensure the exclusivity principle of arc relationships? (Assume that you are implementing an Exclusive Design) (Choose Two) (Choose all correct answers) -Make all relationships mandatory -Make all relationships optional -Create an additional check constraint to verify that one foreign key is populated and the others are not -All the above

-Make all relationships optional -Create an additional check constraint to verify that one foreign key is populated and the others are not

In an Oracle database, why would 1_TABLE not work as a table name? -The database does not understand all capital letters. -TABLE is a reserved word. -There is no problem here. You can create a table called 1_TABLE. -Object names must not start with a number. They must begin with a letter.

-Object names must not start with a number. They must begin with a letter.

Identify all of the incorrect statements that complete this sentence: A primary key is...(Choose three) (Choose all correct answers) -One or more columns in a table that uniquely identifies each row in that table. -Only one column that must be null. -A single column that uniquely identifies each column in a table. -A set of columns in one table that uniquely identifies each row in another table.

-Only one column that must be null. -A single column that uniquely identifies each column in a table. -A set of columns in one table that uniquely identifies each row in another table.

Why would this table name NOT work in an Oracle database? this_year_end+next_year -Table names must begin with an alphabetic character. -It is too long. -The Plus sign + is not allowed in object names. -None of the above.

-The Plus sign + is not allowed in object names.

In an Oracle database, why would the following table name not be allowed 'EMPLOYEE JOBS'? -The database does not understand all capital letters -JOBS is a reserved word -EMPLOYEE is a reserved word -You cannot have spaces between words in a table name

-You cannot have spaces between words in a table name