Detecting redundancy in data warehouse evolution

Theodoratos, D

dc.contributor.author	Theodoratos, D	en
dc.date.accessioned	2014-03-01T01:14:30Z
dc.date.available	2014-03-01T01:14:30Z
dc.date.issued	1999	en
dc.identifier.issn	0302-9743	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/13113
dc.subject	Data Warehouse	en
dc.subject	Materialized Views	en
dc.subject	Satisfiability	en
dc.subject	Time Varying	en
dc.subject.classification	Computer Science, Theory & Methods	en
dc.title	Detecting redundancy in data warehouse evolution	en
heal.type	journalArticle	en
heal.identifier.primary	10.1007/3-540-47866-3_23	en
heal.identifier.secondary	http://dx.doi.org/10.1007/3-540-47866-3_23	en
heal.language	English	en
heal.publicationDate	1999	en
heal.abstract	A Data Warehouse (DW) can be abstractly seen as a set of materialized views defined over a set of remote data sources. A DW is intended to satisfy a set of queries. The views materialized in a DW relate to each other in a complex manner, through common subexpressions, in order to gurantee high query performance and low view maintenance cost. DWs are time varying. As time passes new materialized views are added in order to satisfy new queries or for performance reasons while old queries are dropped. The evolution of a DW can result in a redundant set of materialized views. In this paper we address the problem of detecting redundant views in a given DW view selection, that is, views that can be removed from the DW without negatively affecting the query evaluation or the view maintenance process. Using an AND/OR dag representation for multiple queries and views, we first provide a method for detecting materialized views that are not needed in the process of propagating source relation changes to the DW. Then, we use this method to detect materialized views that are redundant. As a side effect, our approach shows how source relation changes can be propagated to the DW materialized views by exploiting common subexpressions between views and by using other materialized views that are not affected by these changes.	en
heal.publisher	SPRINGER-VERLAG BERLIN	en
heal.journalName	CONCEPTUAL MODELING - ER'99	en
heal.bookName	LECTURE NOTES IN COMPUTER SCIENCE	en
dc.identifier.doi	10.1007/3-540-47866-3_23	en
dc.identifier.isi	ISI:000189459400023	en
dc.identifier.volume	1728	en
dc.identifier.spage	340	en
dc.identifier.epage	353	en