Relational Database Management System Flashcards
Invented Relational Database Management System
Edgar F. Codd
Commercial RDBMS products from numerous vendors started to appear about
1980
Model of database consist of multiple relations/tables
Relational Database
Relational Database Model consists of
- Data structure
- Data Manipulation
- Data Integrity
Columns of data
Fields
Rows of data
Records
Synonym Table
Entity
Using SQL to manipulate data
Data manipulation
organized in table with rows and column
Data Structure
business rules that maintain data integrity
Data Integrity
Unique identifier
Primary key
primary key that consists of more than one attribute
composite key
copy key from other table or reference key
foreign key
Description of overall structure of data base
Schema
Set of valid atomic values for given attribute
Domain
rules that apply to particular relation
Specific integrity rules
rules that apply to all relations
general integrity rules
can be possibly used as primary key
candidate key
Delete rules
Referential integrity rule
The relations in a database must not contain unmatched foreign keys
Referential integrity rule
no null allowed
Entity integrity rule
NO COMPONENT OF THE PRIMARY KEY OF A BASE RELATION IS ALLOWED TO ACCEPT NULLS
Entity integrity rule
dont allow delete of parent side
Restrict
automatically delete dependent when parent side to be deleted
casscade
set foreign key in dependent to null
set-to-null
Business embedded rule expressing constraints of organization
Business Rules
Structure of relation
shorthand notation
is always represented by a single value
atomic
relation stored physically in the database
base relation
deals with how to design relational schema
normalization
