Operational Information
Data history (snapshots, versions); Data ownership; Data extract audit trail; Data usage data; Used by the load, management, and
Metadata
Metadata answers the following types of question: • What information is available, by subject area, and
when did we start collecting that data? • How was this summarization created? • What queries are available to access the data? • What business assumptions have been made? • How do I find the data I need? • How old is the data? • What does that value mean?
Metadata
Metadata can be classified into:
Technical metadata that contains information about data warehouse data for use by data warehouse designers and administrators when carrying out data warehouse development and management tasks.
Metadata is used throughout the DW, from extraction stage through the access stage.
Metadata is used throughout the DW, from extraction stage through the access stage.
Why Data Modeling Is Important
Visualization of the business world: Generally speaking, a model is an abstraction and reflection of the real world.
Metadata
Metadata contains detailed descriptions of the location, structure, and meaning of data; keys and indexes of the data; the algorithms and business rules used to transform and summarize datMetadata
Metadata is very important in the data warehouse environment. Metadata is often described as 'data about data'. Metadata contains information on the location, the structure, and meaning of data, mapping information, and a guide to the algorithms used for summarization between detail and summary data.
Business metadata contains information that gives users an easy-to-understand perspective of the information stored in the data warehouse.
Data warehouse operational information.
What is Data Modeling
Data modeling has been an art that first gained recognition since Dr. Peter Chen's 1976 article which illustrated his new-found approach called "Entity-Relationship Modeling." Since then it has become the standard approach used towards designing databases. By properly modeling an organization's data, the database designer can eliminate data redundancies which are a key source for inaccurate information and ineffective systems.
access processes for scheduling data loads or end user access.
Metadata Users
Choosing the Metadata Location
Where it is stored is product-specific, the metadata resides in the database and usually on the data warehouse server. This is the preferred method. Metadata may be located on a separate database on another machine.