For Dummies 978-0-470-55741-9 Datasheet download pdf (Page 2)

Part I: Basic Concepts

Keeping Track of Things

Today people use computers to perform many tasks formerly done with

other tools. Computers have replaced typewriters for creating and modifying

documents. They’ve surpassed electromechanical calculators as the best

way to do math. They’ve also replaced millions of pieces of paper, file folders,

and file cabinets as the principal storage medium for important information.

Compared to those old tools, of course, computers do much more, much

faster — and with greater accuracy. These increased benefits do come at a

cost, however: Computer users no longer have direct physical access to their

data.

When computers occasionally fail, office workers may wonder whether

computerization really improved anything at all. In the old days, a manila file

folder only “crashed” if you dropped it — then you merely knelt down, picked

up the papers, and put them back in the folder. Barring earthquakes or other

major disasters, file cabinets never “went down,” and they never gave you an

error message. A hard-drive crash is another matter entirely: You can’t “pick

up” lost bits and bytes. Mechanical, electrical, and human failures can make

your data go away into the Great Beyond, never to return.

Taking the necessary precautions to protect yourself from accidental data

loss allows you to start cashing in on the greater speed and accuracy that

computers provide.

If you’re storing important data, you have four main concerns:

✓ Storing data has to be quick and easy, because you’re likely to do it

often.

✓ The storage medium must be reliable. You don’t want to come back later

and find some (or all) of your data missing.

✓ Data retrieval has to be quick and easy, regardless of how many items

you store.

✓ You need an easy way to separate the exact information you want now

from the tons of data that you don’t want right now.

State-of-the-art computer databases satisfy these four criteria. If you store

more than a dozen or so data items, you probably want to store those items

in a database.

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For Dummies 978-0-470-55741-9 Datasheet Page 2