CSCI 466 Midterm pt. 1

Foreign Key

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

DML

What part of the DBMS would one use to work with the database instance data?

DDL

What part of the DBMS would one use to change the relation schema?

Domain

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

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.

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

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

DML

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, deleting the instance data within the table. Drop deletes everything including the schema.

1NF

no repeating groups, all values must be atomic

2NF

no partial key dependencies

3NF

No transitive dependencies

Database

a collection of of related data

enterprise

a generic term for any reasonably large-scale commercial, scientific, technical, or other application business

operational data

data maintained about the operation of an enterprise

examples of operational data

products, accounts, patients, students, plans

What is a DBMS?

a collection of programs that enables users to create and maintain a database

specifics for defining the database

data types, structures, constraints

instance

current content of a database

schema

data about what the database data represents

domain

set of atomic values of one or more attribute

atomic values

indivisible data values

null value

designates a missing attribute value

degree

number of attributes in a table

cardinality

number of tuples in a table

intention

a named relation and its attribute names

extension

the data in a relation