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2.2. What is Metadata?

Metadata is data about data. A piece of metadata, called a meta object in the Teiid Designer, contains information about a specific information structure, irrespective of whatever individual data fields that may comprise that structure.
Let us use the example of a very basic database, an address book. Within your address book you certainly have a field or column for the ZIP code (or postal code number). Assuming that the address book services addresses within the United States, you can surmise the following about the column or field for the ZIP code:
  • Named ZIPCode
  • Numeric
  • A string
  • Nine characters long
  • Located in the StreetAddress table
  • Comprised of two parts: The first five digits represent the five ZIP code numbers, the final four represent the ZIP Plus Four digits if available, or 0000 if not
  • Formatted only in integer numeric characters. Errors will result if formatted as 631410.00 or 6314q0000
This definition represents metadata about the ZIP code data in the address book database. It abstracts information from the database itself and becomes useful to describe the content of your enterprise information systems and to determine how a column in one enterprise information source relates to another, and how those two columns could be used together for a new purpose
You can think of this metadata in several contexts: