The Business Edge's Loraine Lawson spoke with Evan Levy, a partner at Baseline Consulting and an instructor at The Data Warehousing Institute, about why metadata matters and the business problems it can create.
Lawson: Could you explain what metadata is?
Levy: The whole premise of metadata is, give me the information and context of the data that Im looking at or want to use.
So you might get a five-digit ZIP code, might get a street address, but ultimately what you want to understand is tell me about this data. Where did it come from? If its a field in a database or field in the computer system, where is it located in that computer system? When was it created? So if I want to talk to someone about this information, I can describe what it is, because its not really tangible.
I go to the grocery store and I ask for red delicious apples. When I hold it in my hand, whats metadata about a red delicious apple? Its type, its variety, how much it weighs, where did it come from, when was it picked off a tree - the same thing with data. Metadata is the information about the data.
Lawson: Now when you're designing Web pages and you put in metadata, you put it in the code. Is that how it works for a database too?
Levy: Actually, its funny. There are several different ways that metadata is stored in technology. You just mentioned I could put metadata or comments in the actual Web page, but I think you have to consider one thing. And Im being a little esoteric, so pardon me, metadata is the content or the information about the contents you're talking about.
Now, where its stored is usually the challenge, because there arent standards for how that information is always stored. It varies depending on the type of technology you're talking about. In a database, theres something called a dictionary, but realistically that information isnt always filled in.
Thats actually part of the premise of master data management. Metadata is almost boundless. If you consider the concept of a Social Security number, one would say, well, what about the rules of who is allowed to look at a Social Security number? Someone might say, Hey, thats metadata also. The premise of master data management is being able to decouple all those rules and details about data from where people typically store it, which is in a database or in an application and in fact a mechanism of coupling that information with the data itself. Does that make sense?