Fundamentals of Database DesignPresentation Transcript
Fundamentals of Database Design John Villamil-Casanova Executive Vice President & CIO The Aspira Association 202.835.3600 ext. 123 firstname.lastname@example.org
Agenda Introduction and participants needs We will review “what is a database;” Understand the difference between data and information; What is the purpose of a database system; How to select a database system; Database definitions and fundamental building blocks;
Agenda (2) Database development: the first steps; Quality control issues; Data entry considerations;
What is a database A database is any organized collection of data.Some examples of databases you may encounter in your daily life are: a telephone book T.V. Guide airline reservation system motor vehicle registration records papers in your filing cabinet files on your computer hard drive.
Data vs. information:What is the difference? What is data? Data can be defined in many ways. Information science defines data as unprocessed information. What is information? Information is data that have been organized and communicated in a coherent and meaningful manner. Data is converted into information, and information is converted into knowledge. Knowledge; information evaluated and organized so that it can be used purposefully.
Why do we need a database? Keep records of our: Clients Staff Volunteers To keep a record of activities and interventions; Keep sales records; Develop reports; Perform research Longitudinal tracking
What is the ultimate purpose of a database management system? Is to transform Data Information Knowledge Action
More about database definition What is a database? Quite simply, it’s an organized collection of data. A database management system (DBMS) such as Access, FileMaker, Lotus Notes, Oracle or SQL Server which provides you with the software tools you need to organize that data in a flexible manner. It includes tools to add, modify or delete data from the database, ask questions (or queries) about the data stored in the database and produce reports summarizing selected contents.
Let’s explore some examples Outlook contacts Aspira Association MIS KidTrax GIS-GPS systems
Types of Databases Non-relational databases Non-relational databases place information in field categories that we create so that information is available for sorting and disseminating the way we need it. The data in a non-relational database, however, is limited to that program and cannot be extracted and applied to a number of other software programs, or other database files within a school or administrative system. The data can only be "copied and pasted.“ Example: a spread sheet Relational databases In relational databases, fields can be used in a number of ways (and can be of variable length), provided that they are linked in tables. It is developed based on a database model that provides for logical connections among files (known as tables) by including identifying data from one table in another table
Selecting a Database Management System Database management systems (or DBMSs) can be divided into two categories -- desktop databases and server databases. Generally speaking, desktop databases are oriented toward single-user applications and reside on standard personal computers (hence the term desktop). Server databases contain mechanisms to ensure the reliability and consistency of data and are geared toward multi-user applications.
Selecting a database system: Need Analysis The needs analysis process will be specific to your organization but, at a minimum, should answer the following questions: How many records we will warehouse and for how long? Who will be using the database and what tasks will they perform? How often will the data be modified? Who will make these modifications? Who will be providing IT support for the database? What hardware is available? Is there a budget for purchasing additional hardware? Who will be responsible for maintaining the data? Will data access be offered over the Internet? If so, what level of access should be supported?
Some Definitions A File: A group or collection of similar records, like INST6031 Fall Student File, American History 1850-1866 file, Basic Food Group Nutrition File A record book: a "rolodex" of data records, like address lists, inventory lists, classes or thematic units, or groupings of other unique records that are combined into one list (found in AppleWorks, FileMaker Pro software). A field: one category of information, i.e., Name, Address, Semester Grade, Academic topic A record: one piece of data, i.e., one student's information, a recipe, a test question A layout: a design for a database that contains field names and possibly graphics. Database glossary
Tables comprise the fundamental building blocks of any database. If you're familiar with spreadsheets, you'll find database tables extremely similar. Take a look at this example of a table sample database: The table above contains the employee information for our organization -- characteristics like name, date of birth and title. Examine the construction of the table and you'll find that each column of the table corresponds to a specific employee characteristic (or attribute in database terms). Each row corresponds to one particular employee and contains his or her information. That's all there is to it! If it helps, think of each one of these tables as a spreadsheet-style listing of information. Fundamental building blocks
Where do we start? Let’s explore your “paper system” Client intake forms Job application form Funders reports Database modeling: Define required fields from “forms” or required reports Avoid repetition Keep it simple Identify a unique identifier or primary key
Some Quality Control Considerations Remember “garbage in – garbage out”. Some examples and how to prevent this. Quality management encompasses three distinct processes: quality planning, quality control, and quality improvement Quality Planning in relation to database systems design: Who will perform data entry? Training? On-line help? How data entry will be performed?
Data entry considerations Define “must” enter fields – no record is complete unless: such and such is entered; Make data entry fool proof. Example: Grade level can be entered as a number (8 or 8th or eight). By using a pull-down menu with the correct data format these mistakes can be avoided.
Data Entry – additional considerations Barcode scanners USB or Wireless attached to a Palm or Pocket PC Pocket PC WiFi 802.11g, Bluetooth Wireless networks (real-time on demand systems)