Specification and Management of Interdependent Data in OperationalSystems and Data Warehouses

  • Authors:

  • Dimitrios Georgakopoulos;George Karabatis;Sridhar Gantimahapatruni

  • Affiliations:

  • GTE Laboratories Incorporated, 40 Sylvan Road, MS-62, Waltham, MA 02254/ E-mail: dimitris@gte.com;Bellcore, 445 South Street, Morristown, NJ 07960/ E-mail: georgek@bellcore.com;Sybase Incorporated, 6601 Bay Street, Emeryville, CA 94608/ E-mail: ganti@sybase.com

  • Venue:
  • Distributed and Parallel Databases
  • Year:
  • 1997

Quantified Score

Hi-index 0.00

Visualization

Abstract

({\it Inter}){\it Dependent} objectsinclude data replicated or cached in multiple database systems, datacollected and summarized in data warehouses for analysis, planning,and decision support, as well as any other category of objects whosestates are related and they are maintained in different informationsystems. In this paper we discuss dependencies between objects in anenvironment consisting of operational systems and a data warehouse,and describe their specification and enforcement. To specify objectdependencies we introduce {\it Object\ Dependency\ Descriptors}({\it ObjectDDs}). These describe the relationships between dependent objects, and define howmuch inconsistency between original objects and theirreplicas/collections/summaries can be tolerated before it isnecessary to restore their consistency. Object dependencies areenforced by {\it extended\ transactions} designed specifically forevaluating if dependent objects satisfy their specifiedrelationships, evaluating whether possible inconsistencies can betolerated, and (if not) restoring consistency. To describe thetransactional behavior of such {\it consistency\ evaluation} and {\it restoration} transactions we use{\it Transaction\ Dependency\ Descriptors}({\it TransactionDDs}). TransactionDDsdefine the transactional relationships between consistency evaluation andrestoration (asynchronous) transactions, as well as the relationshipsbetween such asynchronous transactions and regular (synchronous)transactions executed directly by applications. To automaticallymaintain the consistency of dependent objects, we propose the conceptof a {\it Dependency\ Management\ System}({\it DMS}). A DMS monitors dependent objects, evaluates object consistency, and schedules andcontrols consistency restoration transactions to keep dependentobjects within acceptable consistency levels. We describe keycomponents in the DMS architecture, and a relatively simpleimplementation involving straightforward extensions in a relationalDBMS.