Create a supertype when something can be many different subtypes
Create a bridging entity between student and class like enrollment, cant have a many to n
What is a derived attribute? It does not need not be physically sotred within the database.
David J. Murphy-Longhini 37427030 [email protected]
MGS 404 Fall 2013
Homework 1 Due 9/25 @ 3:30pm
NOTE: If you choose to submit the homework electronically please send it from your
@buffalo.edu email address and make sure the file is named following t
MGS 404 Database Management Systems
Midterm 1 Sample Questions
PART 1 True or False:
1. Data processing can be as simple as organizing data to reveal patterns.
2. M:N relationships are not appropriate in a relational model.
3. The enti
4) A database designer should consider should consider using subtypes when attributes exist that
apply to some, but not all, instances of an entity. The database designer should also consider
field combination control
a control that reviews combinations of data inputs to ensure that the
correct data are entered
a control that restricts which persons or programs can add, modify, or
view information resources
Complex update contro
First normal form ( 1NF)
restriction that all rows of a table must contain the same number of
columns (No Repeating attributes)
a one-to-one association between the values of two attributes
Single database server architecture
Routine that converts a primary key value into a relative record number
or relative file address
Distribution of the rows of a logical relation into several separate tables
Table used to determine in a file th
Stores metadata, manages information processing environment and
combines information about an organization's business information and
Information Resource Dictionary System
Computer software tool used to manage
Key- value stores
stores key value pairs, fast lookup key -> value
good for simple associative data and big data
bad for complex highly relational data
Create, Read, Update, Delete
LIKE operator ( SQL)
in SQL - allows you to select only rows that are "like" what you specify.
The percent sign "%" can be used as a wild card to match any possible
character that might appear before or after the characters specified.
select first, last,
A method used to monitor concurrent access to data in which one
transaction is denied access to data until another transaction is complete.
A number of special properties or constraints that a relation must possess
to achieve certain d
Primary key whose value is unique across all relations
Entity Integrity Rule
No primary key attribute may be null
Relation that has a primary key and in which there are no repeating
Attribute in a relation that serves
Drop ( SQL)
The drop table command is used to delete a table and all rows in the
table. drop table is different from deleting all of the records in the table.
Deleting all of the records in the table leaves the table including column
and constraint inform
A client that performs the bulk of the data-processing operations.
flat- file database
A file containing records that have no structured interrelationship.
A column or concatenated columns that are identical to the primary key
Process of transforming normalized relations into non-normalized physical
Contiguous section of disk storage space
Smallest Unit of Application data recognized by system software
The rejoining of relations that were decomposed during normalization.
An attribute or group of attributes on which another attribute is
The allowable values for an attribute.
an integrated collection of stored data that is centrally managed and
Database management system
a system software component that manages and controls one or more
Physical data store
database component that stores the raw bit
An application program used to perform a series of database activities
(CRUD) on behalf of database users
Database Management System
Software system that is used to create, maintain and provide access to
Protection of database data against accidental or intentional loss,
destruction, or misuse
Data warehouse refers to large amounts of data which are stored
together, usually in a single
location, for further processing (
A staged (mathematical) process which removes repeated groups of data
Restructured data in normalized form
Allows the person using the database to clearly see where the information
has come from, and simplifies the i
Explain the term Data Consistency
Data consistency is the relationship between the input data, the processed
data and the output data as well as other related data. If the system is
working properly the data will be correct a
Instance of a supertype may simultaneously be a member of two
Partial Specialization Rule
Entity instance of a supertype is allowed not to belong to any subtype
Process of defining one or more subtypes of the supertype
The part of a nonprocedural DML that retrieves data from a database.
An entity relationship in which an entity is involved in a relationship with
A relational constraint stating that ever
1 #17 (accidental omission)
17) I observed that the process of combining the different user views can create attributes not
included in original views. I would not change the user views.
11. Mandatory One, Mandatory Many, Optional One, Optional Many. SEE DIAGRAMS
a) Yes, a customer may have 0, 1, or many plans.
b) Yes, the minimum cardinality of the belongs relationship from the Customer t
a test to determine whether a method, class, subsystem, or system meets
an integration test of an entire system or independent subsystem
Performance test or stress test
an integration and usability test that de
A unique identifier assigned by a DBMS to a transaction.
A single event or sequence of actions such as a database update or data
retrieval operation that is treated as a unit, both to satisfy a request and
to ensure database integrit
Symmetric key encryption
encryption method that uses the same key to encrypt and decrypt the
Asymmetric key encryption
encryption method that uses different keys to encrypt and decrypt the
Public key encryption
a form of asymmetric key encryptio
Supertype/ Subtype Hierarchy
Hierarchical arrangement of supertypes and subtypes in which each
subtype has only one supertype
Total Specialization Rule
Each entity of a supertype must be a member of some subtype in the
Universal Data Model