WebJun 28, 2024 · (A) A->B, B->CD (B) A->B, B->C, C->D (C) AB->C, C->AD (D) A ->BCD Answer: (C) Explanation: Background : Lossless-Join Decomposition: Decomposition of R into R1 and R2 is a lossless-join decomposition if at least one of the following functional dependencies are in F+ (Closure of functional dependencies) R1 ∩ R2 → R1 OR R1 ∩ R2 → R2 WebDecompose the above relation into two relations to check whether a decomposition is lossless or lossy. Now, we have decomposed the relation that is Employee and Department. Relation 1 : Table Employee Schema contains (Eid, Ename, Age, City, Salary). Relation 2 : Table Department Schema contains (Deptid, Eid, DeptName).
What is lossy and lossless decomposition in dbms with examples
WebNov 27, 2015 · If we go through all the FD's and none of the rows of our table get completely filled with a then it is a lossy decomposition. Also, note if it is a lossy decomposition we can always make it lossless by adding one more relation to our set of decomposed relations consisting of all attributes of the primary key. WebDetermining Whether Decomposition Is Lossless Or Lossy-. Consider a relation R is decomposed into two sub relations R 1 and R 2. Then, If all the following conditions … biobed agricolo
Difference between Lossless and Lossy Join …
Web1. Create an initial matrix S with one row i for each relation in Ri in D, and one column j for each attribute Aj in R. 2. Set S (i, j) := bij for all matrix entries. (* each bij is a distinct … WebDec 11, 2016 · In summary, a lossless decomposition is an important concept in DBMS that ensures that the original relation can be reconstructed from the decomposed relations … Decomposition of R into R1 and R2 is a dependency preserving decomposition if … A Computer Science portal for geeks. It contains well written, well thought and … WebApr 11, 2024 · A Computer Science portal for geeks. It contains well written, well thought and well explained computer science and programming articles, quizzes and practice/competitive programming/company interview Questions. daffy duck movie fantastic island granny