Time In Databases(Cont.) Example of a temporal relation: ID name dept name salary from to 10101 Srinivasan Comp.Sci. 61000 2007/1/1 2007/12/31 10101 Srinivasan Comp.Sci. 65000 2008/1/1 2008/12/31 12121 Wu Finance 82000 2005/1/1 2006/12/31 12121 Wu Finance 87000 2007/1/1 2007/12/31 12121 Wu Finance 90000 2008/1/1 2008/12/31 98345 Kim Elec.Eng. 80000 2005/1/1 2008/12/31 Temporal query languages have been proposed to simplify modeling of time as well as time related queries. Database System Concepts-6th Edition 25.4 @Silberschatz,Korth and SudarshanDatabase System Concepts - 6 25.4 ©Silberschatz, Korth and Sudarshan th Edition Time In Databases (Cont.) Example of a temporal relation: Temporal query languages have been proposed to simplify modeling of time as well as time related queries