Types of Metadata - Teradata Database

Metadata has been around for as long as there have been programs and data. However, in the world of data warehouses, metadata takes on a new level of importance. Using metadata, you can make the most effective use of Teradata. Metadata allows the decision support system (DSS) analyst to navigate through the possibilities.

The major component of the DSS environment is archival data, that is, data with a timestamp. Because archival data is timestamped, it makes sense to store metadata with the actual occurrences of data, which are time stamped as well.

The following table describes the types of metadata.

For the…	The following types of metadata are stored…
data model	Description Specification The layout of the physical data model tables Relation between the data model and the data warehouse
data warehouse	Data source (system of record) Definition of the system of record Mapping from system of record to the data warehouse and other places defined in the environment Table structures and attributes Any relationship or artifacts of relationships Transformation of data as it passes into the data warehouse History of extracts Extract logging Common routines for data access
columns	Columns in a row Order in which the columns appear Physical structure of the columns Any variable‑length columns Any columns with containing NULLs Unit of measure of any numeric columns Any encoding used
database design	Description of the layouts used Structure of data as known to the programmers and analysts