Title: HAP 709: Healthcare Databases
1HAP 709 Healthcare Databases
- Introduction to Database Structures
- Janusz Wojtusiak, Ph.D.
- Fall 2010
- Based on slides by
- Farrokh Alemi, Ph.D.
- Francesco Loaiza, Ph.D. J.D.
2What is a database?
- Is an Excel table with students grades a
database? - Is your notebook a database?
- Is a phonebook a database?
- Is the GMU schedule of classes a database?
- Is a medical record of a patient a database?
- Is a list of nurses working in a hospital a
database?
3What is database?
- Database is a collection of data with defined
structure and purpose. - Wikipedia A Database is a structured collection
of data which is managed to meet the needs of a
community of users. - Wordnet Database is an organized body of related
information.
4What is computer database?
- Computer database is a database stored in a
computer. - It is usually managed by special software called
Database Management System (DBMS). - There are many DBMS systems available
- Access, Oracle, MUMPS, dBASE, portgress, sql
server, mysql, db2,
5Objectives of this lecture
- Learn about flat, hierarchical, relational, and
object-oriented databases - Learn about information-less databases
If checking an information item takes a fraction
of a second, why is it that we search through
billions of information items in a fraction of
a second?
6Types of Data Structures
- Flat data
- Hierarchical data
- Relational data
- Object-oriented data
7Flat Models
8Flat Data
- How do we keep two addresses for the same
student? - What if there are five addresses?
9Flat Data
- Advantages
- Most software include free access to flat data
files. For a small number of cases, flat
databases do a reasonably fast job. - Most analytical software use flat data.
- Disadvantages
- Flat databases waste computer storage by
requiring it to keep information on items that
logically cannot be available - It is almost impossible to design flat models for
things with varying numbers of properties - Flat databases are not conducive to complicated
search queries
10Hierarchical models
- Data models in which the relationship between
higher and lower items are inherited.
11Example of Hierarchal Model
Person
Patient
Employee
Contractor
ICU
Admin
Clinical
Clinic
12Advantages of Hierarchical Models
- Advantages
- Operations on parents save time and affect all
children. - Disadvantages
- Many relationships are not hierarchical
13Relational Databases
In a relational data base, one stores a record
with related fields as data.
- In a relational database, tables do not need to
be of the same size
14Example
Table for "Students grades"
Table for "Students' contact information"
15Advantages of Relational Databases
- Data can be examined from many different
perspectives. - No need to enter missing information for
variables that are not logically possible. - Easy to modify because adding new concepts
involves adding new Tables, not altering old ones.
16Object-oriented data models
- Data are organized in the form of objects that
represent real world entities. Each objects have
its properties, that can be regular values or
other objects.
17Advantages of Object-oriented models
- Advantages
- High efficiency
- Use of the actual real life entities as objects
- Integration with object-oriented programming
languages (C, Java, C ) - Disadvantages
- Lack of one good standard
18Distributed data models
- Data are kept in different settings and on
different computers. Distributed databases need
not only addresses for where the data are but
also need an audit trail - HAP 720
19Advantages and Disadvantages of Distributed
Databases
- Security of these databases are difficult to
maintain. - Many agreements must be made ahead of time.
- Data loss is limited to nodes affected.
- Decentralized databases are more flexible and
allow different units to update and maintain
their own data. - Variation in quality of data
20Data-less Information Systems
- Distributed Databases without data until need
arises, less problems with privacy of patients - Sometimes called federated databases.
21 Components of a Data-less System
- Decoder
- Communicator
- Analysis
22Advantages of the Data-less Information Systems
- The system is substantially less expensive than
centralized registries as it requires no new
equipment and little personnel. - The system does not require duplication of data
in different databases.
23Inductive Databases
- Researchers investigate databases that can answer
questions about things which are not explicitly
in that databases. They use artificial
intelligence to give plausible answers.
24Take Home Lesson
- Structure makes it possible to process and
analyze large amount of data