DBMS: Redundancy (Definitions)

"A general term that refers to the capability of an organization to recover from critical database. Redundancy generally involves having more than one source for data, which could be as simple as a backup." (Owen Williams, "MCSE TestPrep: SQL Server 6.5 Design and Implementation", 1998)

"A system that has been set up so that failure at one point does not cause failure of the entire system." (Owen Williams, "MCSE TestPrep: SQL Server 6.5 Design and Implementation", 1998)

"Storing more than one occurrence of the data." (Ralph Kimball & Margy Ross, "The Data Warehouse Toolkit" 2nd Ed., 2002)

"the practice of storing more than one occurrence of data. In the case where data can be updated, redundancy poses serious problems. In the case where data is not updated, redundancy is often a valuable and necessary design technique." (William H Inmon, "Building the Data Warehouse", 2005)

"The storage of multiple copies of identical instances of a thing (database, table, record, or value)." (Sharon Allen & Evan Terry, "Beginning Relational Data Modeling" 2nd Ed., 2005)

"Here, the provision of information beyond necessity." (Martin J Eppler, "Managing Information Quality" 2nd Ed., 2006)

"The storage of multiple copies of logically identical data. Physically, the data may or may not be identical across systems, and it is not known which is most current or accurate." (DAMA International, "The DAMA Dictionary of Data Management", 2011)

"The assurance of availability by providing duplicate systems or alternative processes." (Mark Rhodes-Ousley, "Information Security: The Complete Reference" 2nd Ed., 2013)

"Surplus capability, which is maintained to improve the reliability of a system." (Manish Agrawal, "Information Security and IT Risk Management", 2014)

"Process of providing alternative resources in order to continue the execution despite any component failures." (Hamid R Arabnia et al, "Application of Big Data for National Security", 2015)

"Multiple occurrence of the same information in different places." (IQBBA, "Standard glossary of terms used in Software Engineering", 2011)