Discussion - Week 3

Managing Data

Information systems require access to data. The program examples so far have relied largely upon user inputs for this data, but most information systems are built upon one or more databases that maintain extensive information. Another source of information is independently stored information, like the current system date in the birthday calculator program or like cookies with website information. Common forms of data accessed by programs in information systems include:

direct user inputs

locally stored variables

local files

local databases

remote session files

remote databases

Programs not only retrieve data from these but also write information to them.

As an example, the Discussion forum here relies on retrieving information about you and your colleagues from a user database. When you log in, the program contained in scripts embedded in the Discussion forum establish a session so that as you navigate through your classes, it still knows who you are. The Discussion forum also has to access a database that contains the content of all of the posts and tracks what post each replies to, when it was posted, and who posted it. The program supporting the Discussion forum has to be able to pull all of these posts and organize them in the thread. You can also write content to that post database by replying in a thread. In addition to interacting with these databases, the Discussion forum also accesses files that tell how everything should appear in the browser. All of this data has to be stored and must be easily and systematically retrievable. Data is at the heart of information systems.

Give an example of a specific information system that you are familiar with, and describe at least three different ways that programs within that system access, store, and manage data. Please include at least one example of a program retrieving data and one example of the program writing data.

By Day 3

Post a response.

By Day 6

Respond to at least two colleagues by Day 6 by reflecting on why the data described is stored in the identified format (local variable, local file, local database, remote file, or remote database). If another data format might better meet this need, discuss why.

Continue the conversation by discussing the merits of the various data formats in this context.