Multi-version data warehouse: A survey

A data warehouse (DW) is a data store that is mainly used to store integrated information from various heterogeneous data sources for the purpose of querying and detailed analysis. These data sources are operational systems that can undergo changes in their contents (data changes) as well as in their structures (schema changes) due to continual evolving users´ requirements. The DW is considered as the core component for business intelligence applications and needs to be updated following evolution of underlying operational systems. Traditional DW systems provide minimal support for the evolution of their structures. A multi-version data warehouse (MVDW) offers a promising solution in this direction that avoids information loss as well as provides support for simulating hypothetical business scenarios. A multi-version data warehouse is a collection of the set of its versions, each of which includes a schema version and an instance version. In this paper, we have done a comprehensive study of the research works of various authors in the area of DW versioning.