Relational Database Model

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Relational Database Model
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Database
A collection of information organized in such a
way that a computer program can quickly select
desired pieces of data. You can think of a
database as an electronic filing system.
Traditional databases are organized by fields,
records, and files. A field is a single piece of
information a record is one complete set of
fields and a file is a collection of records.
For example, a telephone book is analogous to a
file. It contains a list of records, each of
which consists of three fields name, address,
and telephone number.
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Database
Name John Corb Address 300 Hebert
Hall Phone [phone]
File
Fields
Record
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Other Terms Used

• File Table Entity
• Record Row Tuple
• Field Column Attribute

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Example
Field, Column, Attribute
Key field/ Unique Identifier
File, Entity, Table Contacts
Record, Row, Tuple
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Relational Database Model
Entity Relationship Modeling involves
identifying the things of importance in an
organization (entities), the proprieties of those
things (attributes) and how they are related to
one another (relationships). (Barker, Richard.
Entity Relationship Modeling. Oracle 1992)
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Data Manipulation

• Relational Allocation
• One-to-one, one-to-many, many-to-many
• Relational Algebra Operations
• Union, intersection, difference, product,
  restriction, projection, join and division
• Data Processing Language
• Series of clauses to perform data processing
  queries using SQL (Structured Query Language)

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Normalization
Normalization of data is a procedure to ensure
that a data model conforms to some useful
standards. For data and entity relantioship
models, these standards have been defined to
minimize duplication of data, to provide the
flexibility necessary to support different
funcional requirements, and to enable the model
to be mapped onto a wide variety of alternative
database designs. (Barker, Richard. Entity
Relationship Modeling. Oracle 1992)
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Third Normal Form (TNF)

• First Normal Form
• Remove repeated attributes or groups of
  attributes.
• Second Normal Form
• Remove attributes dependent on only part of the
  unique identifier.
• Third Normal Form
• Remove attributes dependent on attributes that
  are not part of the unique identifier.

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Normalization Example
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Colombia Health Facilities
One-to-many