2 2 votes Consider $X(A,B,C,D,E,F)$ with $F=\{AB\to CD,\ CD\to EF\}$.The relation is decomposed into $X_1(A,B,C,D)$ and $X_2(C,D,E,F)$.Which statement is correct?The decomposition is lossless but not dependency preserving. The decomposition is dependency preserving but lossy. The decomposition is both lossless and dependency preserving. The decomposition is neither lossless nor dependency preserving. Databases goclasses goclasses-da-dpp goclasses-da-dpp-day-274 goclasses-cs-dpp goclasses-cs-dpp-day-372 databases goclasses-databases-practice-questions dependency-preserving lossless-join + – GO Classes 116 views answer comment Share Follow Print See all 5 Comments 5 5 Comments reply Show 2 previous comments Prashant-G commented 2 days ago reply Follow flag @GO Classes sir only 5 Question are there in DS DPP , bo bhi almost 45 days pehle upload huye the tb se koi question upload nhi hua you can check sir This is the link https://gateoverflow.in/tag-search-page?q=goclasses-cs-dpp-day-313+data-structures 0 0 replyShare GO Classes commented 2 days ago reply Follow flag @Prashant-G We have created a lot of DPPs on DS and Algo.The Data Structures DPPs started from 3rd July. The first DS DPP is DS DPP 1.If you want to follow the DPPs day-wise, you can access all of them from our page, start from July 3rd.However, if you want to access all the Data Structures DPPs together at one place, use this link. 1 1 replyShare Prashant-G commented 2 days ago reply Follow flag @GO Classes thankyou so much for the link sir actually me yaha se Dpp access krta tha but yaha DS mention nhi hai so I thought not started ,i think team forget to mention DS here, thanks again I was literally waiting for 2 month of DS Dpp 0 0 replyShare Please log in or register to add a comment.
1 1 vote First check the binary lossless condition.$X_1\cap X_2=\{C,D\}$.For a binary decomposition to be lossless, the common attributes must functionally determine all attributes of at least one component.We have $CD\to EF$.Therefore, $CD\to CDEF$.But, $CDEF=X_2$.Hence,$(X_1\cap X_2)\to X_2$.Therefore, the decomposition is lossless.Now check dependency preservation.The FD $AB\to CD$ can be enforced entirely inside $X_1(A,B,C,D)$.The FD $CD\to EF$ can be enforced entirely inside $X_2(C,D,E,F)$.Thus both original dependencies are preserved locally.Therefore, the decomposition is also dependency preserving.Hence, the correct answer is C. GO Classes answered 2 days ago GO Classes comment Share Follow 0 reply Please log in or register to add a comment.
