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From Data to Intelligence
Now that you've been introduced to databases, we can take a closer look at what a relational database is, how they work, and how they are used to build business intelligence.
Posted by Mark Hemphill on November 14, 2007 in Module III - Software | Permalink
Comments
With a relational database, am I right to think that it has a certain amount of information already stored within itself? Does the database look to other sources for information if a client requests information it doesn't already contain?
Posted by: Karen Deveaux | Nov 20, 2007 7:42:20 AM
I think that...A relational database is completely void of any data until you it, or write/utilize a software application to insert data. Typically you create the database, then you create the tables you want within it, then fill in the data elements into the tables (often using a software application). The database itself is unable to look to any other sources of information if requested data is not in the table. In simplistic terms, the clients requests for a data element must be made in a query language (either explicitly or through an interface in the RDMS) which inherently has no event handling. The database will just answer your question: yes-and here is the data, or no we couldn't find it. The interface in your RDBMS however, may have programming logic which will ask you what you want to find, translate it into a query, query the database, and either return the result or perhaps have event handling to try a similar query if your first request is not found.
Posted by: Ben Howard | Nov 20, 2007 10:53:12 AM
A relational database in my opinion is a list of things that are needed in a logical order of necessity...I may be way off. It aligns what is needed, by why it is needed and maybe where it is needed and how it is to be used. If everything on the list is cross-referenced it makes it easily read and followed. Then when it is entered into a software program it can manage the data and make the needed alignments for it to become integrated and make sense to its users.
Posted by: Frieda MacLaren | Nov 20, 2007 12:31:28 PM
There have been a few definitions of RDBMS here. Here is my attempt at it....
An RDBMS is a database which groups its data into entities which are related and then defines relations between those different entities. For example, a database storing customer information may define a "customer" entity and an "address" entity within the database. Each customer can be linked to one or more addresses. The "address" entity can also be broken down into different entities including "town", "province", and "Postal Code", etc. Each of these entities can be stored independently of one another, but relations are defined among these entities to make them meaningful.
That is my stab at defining what an RDBMS is. Hope it makes sense.
Posted by: Cory | Nov 22, 2007 7:46:40 AM
So one spreadsheet would be a database but interconnected spreadsheets (via formulas) would be a relational database. Pretty simple...or so I think.
Posted by: Chad MacLean | Nov 22, 2007 12:27:12 PM
Cory, you pretty much nailed it. The one clarification I would make is that an RDBMS is a software tool that helps you organize your database using the relational approach. There is a difference between the database and the software tool used to create and manage it.
@Chad, the relational approach to managing a database refers to the way in which data is structured and interlinked. You could probably try to create one using spreadsheets as you say, using formulas and macros, but a relational database management system (RDBMS) would be the more appropriate tool in most cases.
Posted by: Mark | Nov 22, 2007 12:57:43 PM
ok now im starting to put some of this database stuff together,, Some of the terms I recognize from the IT111 labs. We had to make databases and use the primary and foreign keys
Posted by: Johnny Kelly | Nov 28, 2007 3:57:15 PM
Mark, I think I'm understanding what a relational database is because it is a database that connects and interlinks entitities according to relation. But, wouldn't most databases be relational. What would a plain DBMS be used for?
Posted by: Krista Mackenzie | Nov 29, 2007 11:15:29 PM
From the PPT presentation is a primary key like the main part of a database and then the foreign key is any primary key in another?
Posted by: Colin Butler | Dec 4, 2007 10:54:06 PM
