CSCI 466 pt.2

An attribute or set of attributes within one relation that matches the candidate key of some other relation is called a what?

foreign key

What part of the DBMS handles database instance data?

DML

What part of the DBMS changes the relation schema?

DDL

The set of allowable values for an attribute in a relational database schema is called what?

Domain

The Entity Integrity Rule states:

The primary key must be unique and cannot be NULL

A Tuple is

Another name for a "row" in a relation.

What must be true of a table in First Normal Form?

No duplicate groups

Assuming a relation is already in First Normal Form, what needs to be true for it to be in Second Normal Form?

No partial key dependencies

Assuming a relation is already in Second Normal Form, what need to be true for it to also be in Third Normal form?

No transitive dependencies

Set up the table R(ID, Name, Description). ID should be a number and the primary key. Name and Description will both be strings.

CREATE TABLE R (

ID INT PRIMARY

KEY, Name VARCHAR(256), Description VARCHAR(256));

Add a row into the R table with ID=1, a name of "Anakin SKywalker" and a Description of "Good guy".

INSERT INTO R VALUES(1, 'Anakin Skywalker', 'Good guy');

Change the name to "Darth Vader" and the Description to "Luke's father" to ID 1.

UPDATE R SET Name='Darth Vader',Description='Luke's father' WHERE ID=1;

Remove the entry you made about Darth Vader.

DELETE FROM R WHERE ID=1;

Get rid of the table completely

DROP TABLE R;

An attribute or set of attributes that uniquely identify a tuple is called at

Super Key

a "minimum" set of attributes that uniquely identify a tuple

Candidate Key

One set of chosen candidate keys that uniquely identify a tuple

Primary Key

What does DDL stand for?

Data Definition Language

What does DML stand for?

Data Manipulation Language

Name one difference between "Update table" and "Alter table".

Alter table works with DDL to change columns of table. Update works with the DML to change the actual data in the columns.

The "Select" statement works with the DML or the DDL?

DML

Name one difference between "Drop" and "Delete" table?

Delete keeps the schema and removes the instance data in the table. Drop deletes everything, including the schema.