DBMS: Composite Key (Definitions)

"An index key that includes two or more columns; for example, authors(au_lname, au_fname)." (Karen Paulsell et al, "Sybase SQL Server: Performance and Tuning Guide", 1996)

"A key composed of two or more columns. A drawback of composite keys is that they require more complex joins when two or more tables are joined." (Microsoft Corporation, "SQL Server 7.0 System Administration Training Kit", 1999)

"Key in a database table made up of several columns. Same as Concatenated key. The overall key in a typical fact table is a subset of the foreign keys in the fact table. In other words, it usually does not require every foreign key to guarantee uniqueness of a fact table row." (Ralph Kimball & Margy Ross, "The Data Warehouse Toolkit" 2nd Ed., 2002)

"A key composed of two or more columns." (Anthony Sequeira & Brian Alderman, "The SQL Server 2000 Book", 2003)

"A candidate key made up of more than one attribute or column." (Sharon Allen & Evan Terry, "Beginning Relational Data Modeling" 2nd Ed., 2005)

"A primary key, unique key, or foreign key consisting of more than one field." (Gavin Powell, "Beginning Database Design", 2006)

"Multiple key columns used to uniquely identify a record." (Reed Jacobsen & Stacia Misner, "Microsoft SQL Server 2005 Analysis Services Step by Step", 2006)

"A candidate key comprising more than one attribute." (S. Sumathi & S. Esakkirajan, "Fundamentals of Relational Database Management Systems", 2007)

"A key that includes two or more fields. Also called a compound key or concatenated key." (Rod Stephens, "Beginning Database Design Solutions", 2008)

"A key for a database table made up of more than one attribute or field." (Paulraj Ponniah, "Data Warehousing Fundamentals for IT Professionals", 2010)

"A key whose definition consists of two or more fields in a file, columns in a table, or attributes in a relation." (Microsoft, "SQL Server 2012 Glossary", 2012)

"A key with more than one attribute." (Craig S Mullins, "Database Administration", 2012)

"An ordered set of key columns or expressions where the referenced column names are from the same table. See also key." (Sybase, "Open Server Server-Library/C Reference Manual", 2019)