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Rename Operation Allows us to name,and therefore to refer to,the results of relational- algebra expressions. Allows us to refer to a relation by more than one name. Example: Px(E) returns the expression E under the name X If a relational-algebra expression E has arity n,then Px(4424n)(E) returns the result of expression E under the name X,and with the attributes renamed to A1,A2,....,An Database System Concepts-6th Edition 6.10 @Silberschatz,Korth and SudarshanDatabase System Concepts - 6 6.10 ©Silberschatz, Korth and Sudarshan th Edition Rename Operation Allows us to name, and therefore to refer to, the results of relational￾algebra expressions. Allows us to refer to a relation by more than one name. Example:  x (E) returns the expression E under the name X If a relational-algebra expression E has arity n, then returns the result of expression E under the name X, and with the attributes renamed to A1 , A2 , …., An . ( ) ,..., ) 2 , 1 ( E n  x A A A
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