Fill-in the following statements:

1 .The requirement that the value of a foreign key either be null or
match the value of the primary key in some other relation is known as
___________.
2. The rule that no attribute which participates in the primary key
may accept null values is known as ___________.
3. A one-to-many relationship can be handled by including the primary
key of the "one" relation as a(n) _____________ in the "many"
relation.
4. When users access data at a remote site in the same manner they
access data at the local site the system has ____________.
5. When users need not be aware of the multiple copies kept of a given
item of data, the system has___________.
6. The dividing of occurrences of records of a given type 	among
multiple sites is an example of  _____________________
7. A DDBMS in which the local DBMS's are of different types is a
____________ DDBMS.

Hello skokie,

1. referential integrity
“The rule of referential integrity states that the value of a foreign
key must be within the domain of its related primary key, or it must
be null”
“SQL By Design: The Four Integrities” SQL Server Magazine
http://www.sqlmag.com/Articles/Index.cfm?ArticleID=6200

2. entity integrity
“The entity integrity rule states that no attribute which forms part
of the primary key of a relation can accept null values.”
Notes on Data Integrity on the web site of the University of North
London
http://www.unl.ac.uk/simt/im207/im207week9/im207refint.html 

3. foreign key
“To create a one-to-many relationship, include the primary key of the
“one” table as a foreign key in the “many” table.”
Notes on Database Management Systems on the web site of  Roane State
Community College
http://www.roanestate.edu/faculty/glenn/CST%20208%20%20psuedoscript.htm

4. transparency
“The purpose of transparency is to provide seamless access to all
databases. For example, users should be able to access any table
(provided they have security) in the same method. A table located on a
SYBASE database should be accessible with the same SQL syntax as a
local table. A table located on an Oracle database in Germany should
be accessible with the same syntax as a local table in Detroit.”
Distributed Database Management (chapter from Using Oracle 8)
http://news.dcn-asu.ru/BOOKS/Special.Edition.Using.Oracle8/ch28/0703-0706.html

5. replication
“Replication: Users are unaware of the existence of multiple copies” 
Lecture notes from the University of New South Wales School of
Computer Science & Engineering
This is in the format of a .ps file, but can be viewed in the Google
cache at
http://216.239.53.104/search?q=cache:tLm6SCjvg_0C:www.cse.unsw.edu.au/~cs9243/lectures/week01.ps+replication+users+aware+%22multiple+copies%22+&hl=en&ie=UTF-8

6. fragmentation
“Fragmentation. Different locations store different parts of the
database. Horizontal fragmentation stores different records on
different servers. Vertical fragmentation stores different fields on
different servers. This is good for when different sites need
different data but must still access data elsewhere.”
Distributed DBs , notes on web site of George Hernandez.
http://www.georgehernandez.com/xDatabases/aaIntro/DistributedDBs.htm 

7. heterogeneous 
“A heterogeneous DDBMS uses different DBMSs at the local server.
Integration of the different DBMSs is achieved either through special
software that is part of the DDBMS iself, thus creating what is known
as a multidatabase management system (MDBMS), or through gateways,
which convert query languages and data models across different DBMS.”
Lecture notes on dostributed databases on the web site of City
University, London, UK
www.soi.city.ac.uk/~sjm/courses/mmpp/mmpptxt6.pdf

Search strategy: I used key words from each question in order to
search for documents providing verification of the answers. For
example, for question 1, I my strategy was: value "foreign key" null
"primary key"