Database Systems, Database Management System

Database

Collection of related data that can be stored in a
central location or in multiple locations

File

• Group of related records

• All files are integrated

Record

Group of related fields

Database Management System

Creating, storing, maintaining, and accessing
database files

Internal Data

This are data that is collected withing organization

External Data

This are the sources of the data

Business Intelligence

Used in law enforcement as well as in the business world

Richmond, Virginia

• System generates BI reports that help pinpoint crime patterns

• Allocate manpower to days and locations where crime likely to occur

Sequential File Stracture

Records organized and processed in numerical or sequential order

Primary Key

Sequential File Structure organized based on a

Random Access File Structure

• Records can be accessed in any order

• Fast and very effective when a small number of records need to processed daily or weekly.

Indexed sequential access method(ISAM)

• Records accessed sequentially or randomly

• Depending in the number being accessed

Indexed Sequential Access Method

ISAM means?

Physical View

How data is stored on a and retrieve from stage media

Logical View

• How information appears to users

• How it can be organized and retrieved

• Can be more than one logical view

Data Model

Determines how data is created, represented, organized

Data Structure, Operations, Integrity Rules

Data model includes:

Hierarchical Model

Relationships between records form a treelike
structure

Network Model

• Similar to the Hierarchical Model

• Records are organized differently

Relational Model

Uses a two-dimensional table of rows and columns of data

Data Dictionary

• Field name

• Field data type

• Default value

• Validation rule

Primary Key

Unique identifier

Foreign Key

Establishes relationships between tables

Normalization

• Improves database efficiency

• Eliminates redundant data

• 1NF through 3NF (or 5NF

Structured Query Language (SQL)

• Standard fourth-generation query language used
  by many DBMS packages

• SELECT statement

Structured Query Language

SQL Stands For?

Query by example(QBE)

• Construct statement of query forms

• Graphical interface

Create, Read, Update and Delete

CRUD Stands for?

Data-driven Web Site

• Interface to a database

• Retrieve data and allows user to enter data

Distributed Database

Data is stored on multiple servers place throughout an organization

Fragmentation, Replication and Allocation

Approaches for setup

Client/Server Database

• Users’ workstations (clients) linked in a local area
  network (LAN) to share the services of a single server

• Server processes data

• Returns only records meeting request

Object-Oriented Database

Object consists of attributes and methods

Encapsulation

Grouping objects along with their attributes and
methods into a class

Inheritance

New objects can be created faster and more easily by
entering new data in attributes

Data Warehouse

Collection of data used to support decision-making
applications and generate business intelligence

Extraction, Transformation, and loading

ETL Stands for

Extraction

• Collecting data from a variety of sources

• Converting data into a format that can be used in transformation processing

Transformation Processing

Make sure data meets the data warehouse’s needs

Loading

Process of transferring data to the data warehouse

Online Analytic Processing(OLAP)

• Uses multiple sources of information and provides
  multidimensional analysis

• Generates business intelligence

Data-mining analysis

Discover patterns and relationships

Data Mart

• Smaller version of data warehouse

• Used by single department or function

Reports

Cross-reference segments of an organization’s operations for comparison purposes.