BUS303: Strategic Information Technology

A database is simply a list (or more likely, several related lists) of data. Most organizations have several databases - perhaps even hundreds or thousands. And these various databases might be focused on any combination of functional areas (sales, product returns, inventory, payroll), geographical regions, or business units. Firms often create specialized databases for recording transactions, as well as databases that aggregate data from multiple sources in order to support reporting and analysis.

Databases are created, maintained, and manipulated using programs called database management systems (DBMS), sometimes referred to as database software. DBMS products vary widely in scale and capabilities. They include the single-user, desktop versions of Microsoft Access or Filemaker Pro, Web-based offerings like Intuit QuickBase, and industrial strength products from Oracle, IBM (DB2), Sybase, Microsoft (SQL Server), and others. Oracle is the world's largest database software vendor, and database software has meant big bucks for Oracle cofounder and CEO Larry Ellison. Ellison perennially ranks in the Top 10 of the Forbes 400 list of wealthiest Americans.

The acronym SQL (often pronounced sequel) also shows up a lot when talking about databases. Structured query language (SQL) is by far the most common language for creating and manipulating databases. You'll find variants of SQL inhabiting everything from lowly desktop software, to high-powered enterprise products. Microsoft's high-end database is even called SQL Server. And of course there's also the open source MySQL (whose stewardship now sits with Oracle as part of the firm's purchase of Sun Microsystems). Given this popularity, if you're going to learn one language for database use, SQL's a pretty good choice. And for a little inspiration, visit Monster.com or another job site and search for jobs mentioning SQL. You'll find page after page of listings, suggesting that while database systems have been good for Ellison, learning more about them might be pretty good for you, too.

Even if you don't become a database programmer or database administrator (DBA). These may include (but not necessarily be limited to): database design, creation, implementation, maintenance, backup and recovery, policy setting and enforcement, and security., you're almost surely going to be called upon to dive in and use a database. You may even be asked to help identify your firm's data requirements. It's quite common for nontech employees to work on development teams with technical staff, defining business problems, outlining processes, setting requirements, and determining the kinds of data the firm will need to leverage. Database systems are powerful stuff, and can't be avoided, so a bit of understanding will serve you well.

A complete discourse on technical concepts associated with database systems is beyond the scope of our managerial introduction, but here are some key concepts to help get you oriented, and that all managers should know.

• A table or file refers to a list of data.
• A database is either a single table or a collection of related tables. The course registration database above depicts five tables.
• A column or field defines the data that a table can hold. The "Students" table above shows columns for STUDENT_ID, FIRST_NAME, LAST_NAME, CAMPU.S._ADDR (the "…" symbols above are meant to indicate that in practice there may be more columns or rows than are shown in this simplified diagram).
• A row or record represents a single instance of whatever the table keeps track of. In the example above, each row of the "Students" table represents a student, each row of the "Enrollment" table represents the enrollment of a student in a particular course, and each row of the "Course List" represents a given section of each course offered by the University.
• A key is the field used to relate tables in a database. Look at how the STUDENT_ID key is used above. There is one unique STUDENT_ID for each student, but the STUDENT_ID may appear many times in the "Enrollment" table, indicating that each student may be enrolled in many classes. The "1" and "M" in the diagram above indicate the one to many relationships among the keys in these tables.

Databases organized like the one above, where multiple tables are related based on common keys, are referred to as relational databases. There are many other database formats (sporting names like hierarchical, and object-oriented), but relational databases are far and away the most popular. And all SQL databases are relational databases.

We've just scratched the surface for a very basic introduction. Expect that a formal class in database systems will offer you far more detail and better design principles than are conveyed in the elementary example above. But you're already well on your way!