Your daughter wants to know just what it is that you do all day. She can understand what Caitlin’s father, the airline pilot, does, and what Dakota’s father, the sporting goods store manager does, and she can almost grasp what Zachary’s dad the “lawyer” does — she did see that Jim Carrey movie Liar Liar, after all. But her daddy does something called “databases.” What’s that? As far as she can see, it’s fooling around on a computer all day without playing any cool games.
Your next-door neighbor, the Nobel Prize-winning poet, also wonders what’s this “database” thing he’s heard mentioned recently. So you decide to explain it to both of them at the same time.
One of the best explanations lies in Selena Sol’s wonderful four-part tutorial on databases [http://wdvl.com/Authoring/DB/Intro/what_is_database.html].
Prehistoric Ooze
“Once upon a time,” Sol begins, “in the primitive and barbarian days before computers, the amount of information shepherded by a group of people could be collected in the wisdom and the stories of its older members. In this world, storytellers, magicians, and grandparents were considered great and honored storehouses for all that was known.” In other words, the first database was Og, the medicine man.
Og had his limitations, so the next databases developed were written, like papyri, cuneiform tablets and Rosetta Stones. Eventually they got around to books, soon finding the ultimate form for books in Raymond Chandler novels. The Nobel Prize-winning poet laughs. Your daughter does not.
The first real “databases” as we would call them were libraries, Sol says. The great contribution of libraries is the introduction of standards by which data could be stored and retrieved, making information relatively quickly accessible. “The usefulness of a library, or any base of data, is proportional to its data storage and retrieval efficiency,” Sol says. “This one corollary would drive the evolution of databases over the next 2000 years to its current state.”
The Computer Era
When the modern-day computer was invented around World War II (no, the abacus doesn’t count) it was pressed into service as an information storage and retrieval system. People tried to jam the old library system of classification down the computer’s throat, instead of taking the time to develop a revolutionary way to use a revolutionary product. So the first systems were based on discrete files in a virtual library, Sol explains: “In this file-oriented system, a bunch of files would be stored on a computer and could be accessed by a computer operator. Files of archived data were called ‘tables’ because they looked like tables used in traditional file keeping. Rows in the table were called ‘records’ and columns were called ‘fields’.”
This was a start — a seriously inefficient one, but a start. To find a record, someone would have to read through the entire file and hope what she wanted wasn’t the last record.
So, drawing on another library metaphor, computer scientists came up with a card catalogue, a means to achieve random access processing. This indexed file-oriented system used a single index file to store “key” words and pointers to records that were stored elsewhere. Much better, but the user was still confronted with data redundancy, poor data control and the inability to easily manipulate data. Plus it was usually tough for anyone but a programmer to use it efficiently.
The first truly computer-friendly way to solve this age-old problem of data storage and retrieval was, Sol maintains, the database.
Introducing (Drum Roll) The Database!
“Simply put, a database is a computerized record keeping system,” Sol says. It’s made up the data, the hardware storing that data, and software that both stores the data and retrieves or changes it. Oh, and there’s also you — the user.
“Think of a database as a stockroom for information,” says Web Guild Inc. [http://www.web-guild.com/dbworks.htm] in a helpful introduction. “Everything has a specific place, and each item or group of items is kept in its own container. When you need to retrieve information, you are able to find and access it easily.”
Complex or simple, a database lets you to store data and get it or modify it when you need to, easily and efficiently, no matter how much data is in the pot. (Here you could point your daughter to large mainframes, such as Oracle 8 or Sybase SQL Server as an example.)
People use databases to keep records of various types of information, you tell your daughter. Explain that a typical address book is a simple database. If you need to find a phone number, you look it up under that person’s last name, then by the first name. The same applies to a computer database, Web Guild explains, only the computer allows you to organize the information in many different ways. This is called sorting. You can sort your address book by last name, first name, city, phone number or several other ways; a computer database lets you do the same.
“Yeah, But How Does It Work?”
Good question. Another good explanation on the subject comes from Database Basics from the American Academy of Neurology — evidently you need to be a brain surgeon to understand this stuff. Records or entries in databases have different fields associated with them. Each field is an indicator of a distinct property of that record. A database for medical literature could have fields for authors’ names, article title, journal citation, abstract or other areas. Different databases that organize similar types of data don’t necessarily need to have the same fields — some medical literature databases contain the full text of the articles, while some only contain the abstracts.
Now, how it works, is that a user wants to search the electronic database. She’ll enter keywords into a query form. These keywords are then compared with the data in the database, to see if any stored documents match the keywords. Documents that match are shown to the user.
So basically, this is how a database works:
- Documents are collected. They can be text, images, sounds, whatever fits in a computer.
- The documents are sorted or indexed by category or keywords.
- They are entered into the database.
- Users enter search terms to find entries in the database that match their search queries.
- And hopefully, after all this effort, the users get back the results that they need.
She’ll say, “Is that all? It just keeps track of records?” Well, yes, but there’s more. Not all records are writing. For fun, zip around the Whole Brain Atlas [http://www.med.harvard.edu/AANLIB/home.html] to show her an image database “Wow, neato!”
How about a visit to a seriously cool site: the Guide for the Identification of Japanese Ants database. [http://genetics.bio.kit.ac.jp/ANT.WWW/DOCSE/HOWTO.HTM] “Yuck!”). To show her a database she can search with keywords herself, try the Canadian Crime Prevention Practices Database [http://www.crime-prevention.org/ncpc/council/database/pract ice/index.htm]. “I didn’t know they had any crime in Canada.” There’s a little around Toronto. Mostly drunk American tourists.
“So, What Do You Do Again?”
You explain to the poet that as the database administrator you decide on the best way to store your company’s data and ensure that its quality isn’t lost. You develop and maintain the data dictionary which contains information about the data stored in the database, monitor performance to ensure that access is occurring at optimal speeds, and you fiddle around with restructuring the database or the access methods when it’s not working as well as it could. You keep the security in place, helping make sure only the right people get access to the information. On a daily basis you update the database and make sure that it’s properly maintained. You also keep track of possible future demand for extra computing capacity from the organization, and find ways to deal with that.
“Now I see. How about coming to class Dad so you can tell everyone else. Don’t forget the laptop.”
