A series of posts in response to Tim Ford’s #EntryLevel Challenge.
Part I: Getting started with Oracle Database
Part II: What is a Database?
Part III: What is a Relational Database?
Part IV: What is a Database Management System?
Part V: What makes a Database Management System relational?
Chris Date was the keynote speaker at one of the educational conferences organized by the Northern California Oracle Users Group (NoCOUG), of whose journal I am the editor. The local television news station sent out a crew to cover the event because Chris Date is a well-known database theoretician and one of the associates of Dr. Edgar Codd, an IBM researcher and the inventor of relational database theory. The news reporter cornered me and asked if I was willing to answer a few questions for the camera. I was flattered, but when the reporter pointed the camera at me and asked, “Why are databases important to society?” all I could think of to say was (paraphrasing), “Well, they’re important because they’re, like, really important, you know.” All those years of database administration under my belt, and I still flunked the final exam!
I’d therefore like to spend a few minutes at the outset considering what the word database signifies. An understanding of the implications of the word and the responsibilities that go along with them will serve you well as a good database administrator.
I’ll begin by saying that databases can contain data that is confidential and must be protected from prying eyes. Only authorized users should be able to access the data, their privileges must be suitably restricted, and their actions must be logged. Even if the data in the databases is for public consumption, you still may need to restrict who can update the data, who can delete from it, and who can add to it. Competent security management is therefore part of your job.
Databases can be critical to an organization’s ability to function properly. Organizations such as banks and e-commerce web sites require their databases to be available around the clock. Competent availability management is thus an important part of your job. In the event of a disaster such as a flood or fire, the databases may have to be relocated to an alternative location using backups. Competent continuity management is therefore another important element of your job. You also need competent change management to protect a database from unauthorized or badly tested changes, incident management to detect problems and restore service quickly, problem management to provide permanent fixes for known issues, configuration management to document infrastructure components and their dependencies, and release management to bring discipline to the never-ending task of applying patches and upgrades to software and hardware.
I’ll also observe that databases can be very big. The first database I worked with, for the semiconductor manufacturing giant Intel, was less than 100MB in size and had only a few dozen data tables. Today, databases used by enterprise application suites like PeopleSoft, Siebel, and Oracle Applications are tens or hundreds of gigabytes in size and might have 10,000 tables or more. One reason databases are now so large is that advancements in magnetic disk storage technology have made it feasible to efficiently store and retrieve large quantities of nontextual data such as pictures and sound. Databases can grow rapidly, and you need to plan for growth. In addition, database applications may consume huge amounts of computing resources. Capacity management is thus another important element of your job, and you need a capacity plan that accommodates both continuous data growth and increasing needs for computing resources.
When you start thinking in terms such as security management, availability management, continuity management, change management, incident management, problem management, configuration management, release management, and capacity management, the business of database administration begins to make coherent sense and you become a more effective database administrator. These terms are part of the standard jargon of the IT Infrastructure Library (ITIL), a suite of best practices used by IT organizations throughout the world.
Excerpted from Beginning Oracle Database 12c Administration