4 votes 4 votes Let $R=(A,B,C,D,E,F)$ be a relation scheme with the following dependencies: $C\to F,E\to a,EC\to D, A\to B$. Which of the following is a key for $R$? $CD$ $EC$ $AE$ $AC$ Databases nielit2016mar-scientistb database-normalization candidate-key + – admin asked Mar 31, 2020 • retagged Aug 19, 2020 by Lakshman Bhaiya admin 961 views answer comment Share Follow See 1 comment See all 1 1 comment reply Deepak Poonia commented Nov 11, 2023 reply Follow Share Duplicate of: https://gateoverflow.in/1477/gate-cse-1999-question-1-24 0 votes 0 votes Please log in or register to add a comment.
5 votes 5 votes (A) $CD^{+}=CDF$ (B) $CE^{+}=ABCDEF$ - correct answer (C) $AE^{+}=AEB$ (D) $AC^{+}=ACB$ haralk10 answered Mar 31, 2020 haralk10 comment Share Follow See all 0 reply Please log in or register to add a comment.
1 votes 1 votes When We See a Production Rule Then We Realize That Only C and E Are Not genrated By Any Production Then In the candidate Key It Has To be Presented Only When It Is Prime Attribute . then Option B is Correct.. Or We Also Check Through By Doing Clouser Of Given Key.. Himanshu Kumar Gupta answered Sep 10, 2020 Himanshu Kumar Gupta comment Share Follow See all 0 reply Please log in or register to add a comment.
0 votes 0 votes Ans : b (a) CD+ =CDF EC+ = ABCDE AE+ = AEB AC+= ABCF SO OPTION B IS CORRECT. anjli answered Feb 6, 2021 anjli comment Share Follow See all 0 reply Please log in or register to add a comment.