0 votes 0 votes Consider the relations: $R_{1}${Roll_No, Name, Grades} and $R_{2}${Roll_No, Subject_ID, Grades} Which of the following operations cannot be performed using the above relations? Union Select Join Project Databases databases + – rsansiya111 asked Dec 6, 2021 rsansiya111 291 views answer comment Share Follow See all 0 reply Please log in or register to add a comment.
2 votes 2 votes Answer: A R1 and R2 is not union compatible. SQL UNION Operator (w3schools.com) Set operations (SQL) - Wikipedia raja11sep answered Dec 6, 2021 raja11sep comment Share Follow See all 0 reply Please log in or register to add a comment.