Data Warehouse Metadata [chapter]

Panos Vassiliadis
2016 Encyclopedia of Database Systems  
Data warehouse metadata are pieces of information stored in one or more special-purpose metadata repositories that include (a) information on the contents of the data warehouse, their location and their structure, (b) information on the processes that take place in the data warehouse back-stage, concerning the refreshment of the warehouse with clean, up-to-date, semantically and structurally reconciled data, (c) information on the implicit semantics of data (with respect to a common enterprise
more » ... odel), along with any other kind of data that aids the end-user exploit the information of the warehouse, (d) information on the infrastructure and physical characteristics of components and the sources of the data warehouse, and, (e) information including security, authentication, and usage statistics that aids the administrator tune the operation of the data warehouse as appropriate. HISTORICAL BACKGROUND Data warehouses are systems with significant complexity in their architecture and operation. Apart from the central data warehouse itself, which typically involves an elaborate hardware architecture, several sources of data, in different operational environments are involved, along with many clients that access the data warehouse in various ways. The infrastructure complexity is only one part of the problem; the largest part of the problem lies in the management of the data that are involved in the warehouse environment. Source data with different formats, structure, and hidden semantics are integrated in a central warehouse and then, these consolidated data are further propagated to different end-users, each with a completely different perception of the terminology and semantics behind the structure and
doi:10.1007/978-1-4899-7993-3_912-2 fatcat:3hm3haf5xvdx5ccawyo2rxh5fu