2012.06 History: May Feature: A Brief Introduction to Databases

Presented by Richard S. Russell, summarized by Holly McEntee

Richard began his presentation by explaining that in his retirement he spends a lot of time building, modifying, and maintaining databases for many nonprofit groups and small business. He then defined several terms, distinguishing a "database" (a collection of related information) from a "database manager" (a program or system that renders information accessible, such as for querying and reporting). FileMaker Pro, Richard's preferred app, is a database manager. He went on to explain that database managers generally come in three types: standalone, network, and enterprise. An example of a standalone database manager is Bento, a single-user version of FileMaker Pro. FileMaker Pro itself is a network database manager, because it can be shared across a network of computers or devices (the mobile version of FileMaker Pro is called FileMaker Go — cute, eh?). Enterprise database managers are the most complex — perhaps the best-known enterprise database manager is Oracle. These involve managing multiple back-end and front-end databases and user interfaces to access and use data stored in gigantic centralized mainframe computers.

Richard then explained the difference between flat-file and relational databases. An Excel spreadsheet used for non-accounting purposes is a flat-file database; the public library's catalog MadCat is a relational database in which data (individual fields or entire tables) are linked in multiple ways. These relationships can be one-to-one, one-to-many, many-to-one, or many-to-many, and are established between data fields when a database is designed and built. Lastly, Richard went over common restraints and attributes that can be set for a data field, such as only allowing integers to be entered, not allowing duplicate entries, or never allowing a field to be empty (blank). Data stored in a flat-file database is limited to very simple searches. In general, the more data a database contains, the slower the searches and sorts go.

With all that under the audience's belt, Richard used the remaining time demonstrating these concepts with a basic relational database of colors that he built in FileMaker Pro. He noted that it was a simple database with a single table and four data types, and showed how different queries to the database produced different datasets as a result of the attributes he had assigned the data types. Mad Mac hopes to offer a follow-up to this presentation with one that goes into more detail on specific data types and database structural design. As Richard noted at the end of the evening, designing a relational database takes much careful thought right from the start — even something as simple as a "name" field can become complicated when you take into account the need for a unique field each for first name, middle name, last name, nickname, maiden name, married name....

Richard is willing to send a copy of his initial presentation to you in the form of an RTF document, readable by almost any word processor, if you ask him at RichardSRussell@tds.net.

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