02 June 2006

Databases for Laypeople: Part 2 in a series

(Table of Contents--Part 1)

Most working databases include information in arrays that are far too complex to be viewed as a table, chart, or diagram. Database management software (DBMS) are there to retrieve very specific data on request. An example of this in an actual industrial setting would be the chemistry lab, which collects an immense amount of data on the chemical composition of samples. With potentially hundreds of thousands of chemical samples on file, the lab's client will require the specific results for a particular site collected for a particular day, plus, mandatory records that quality control was applied to the relevant sample batch.

So the DBMS has to be capable of retrieving data. The method of doing this is known as a query. The program will ask you specific questions about the data you want, then fetch it.

One the DBMS has gotten the information you want, however, it has to be in a useful form. Earlier, in order to illustrate the 3D database, I went to the website of the International Labour Organisation (ILO). The data comes back in a gigantic Excel Spreadsheet, which requires some aptitude with manipulating and transposing tables. In contrast, the St Louis Federal Reserve Bank includes a table and chart, different formats for downloading, and so on. Other programs offer detailed reports at the push of a button: MS Access, for example, can be programmed to churn out a boilerplate report complete with elegantly formatted tables. Apache Medical Systems, for example, uses patient databases to aid in diagnostics and clinical trials.
Open Clinical: The APACHE I system was developed by William A. Knaus, an intensive-care physician at George Washington University Hospital, Washington DC, and colleagues from 1978 on. They began collecting and computerizing the experience of intensive care patients from dozens of hospitals. The computer considered each patient as a complicated sum of several variables: diagnosis and physiological abnormalities on admission to the ICU, age, pre-existing medical problems, etc. The system was designed as a way to judge how the hospitals were doing in terms of the mortality rate of its patients.

A physician can give the computer system 27 easily obtained facts, and the program predicts that patient's risk of dying in the hospital. The system is also useful in answering the question: is treatment making a difference? Studies have shown that about half the deaths in American Intensive Care Units now occur after a deliberate decision has been made to stop "heroic" measures. While APACHE does not make such decisions, its advocates say it helps those who must make them ponder the issues in the fairest and most realistic way.
For our purposes, this is a glimpse ahead. It sheds some light on the value of databases: they can make information, especially large amounts of complex information, work for the organization.

In addition to queries to locate data and reports to display them in a usable form, DBMS must allow the data to be input and updated, even while somebody else is using the database from another terminal. This is a part of the problem of database security.

As we shall shortly see, database security is an extremely important, burning issue; it trumps nearly every other consideration from the point of view of DB managers.

(Part 3)

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