R= ABCDEG
decomposition: {AB, BC, ABDE, EG }
F = {AB → C, AC → B, AD → E, B → D, BC → A, E → G}
Is this lossless or not?
Please Draw a table for this, the answer set online told me this is lossy, but when I do the table test, I find it is lossless.
R= ABCDEG decomposition: {AB, BC, ABDE, EG } F = {AB → C, AC → B,...
Let R(A,B,C,D,E) be a relation with FDs F = {AB-CD, A-E, C-D, DE} The decomposition of R into R1(A, B, C), R2(B, C, D) and R3(C, D, E) is (2 Points) Select one: Lossy and Dependency Preserving. Lossless and Not Dependency Preserving. Lossy and Not Dependency Preserving. Lossless and Dependency Preserving.
Let R(A,B,C,D,E) be a relation with FDs F = {AB-CD, A-E, C-D, D-E} The decomposition of Rinto R1(A, B, C), R2(B, C, D) and R3(C, D, E) is 2 Points) Select one: Lossless and Dependency Preserving. Lossy and Not Dependency Preserving. Lossless and Not Dependency Preserving. Lossy and Dependency Preserving.
Let R(A,B,C,D,E) be a relation with FDs F = {AB-CD, A-E, C-D, D-E} The decomposition of Rinto R1(A, B, C), R2(B, C, D) and R3(C, D, E) is 2 Points) Select one: Lossless and Dependency Preserving. Lossy and Not Dependency Preserving. Lossless and Not Dependency Preserving. Lossy and Dependency Preserving.
my choices for these are wrong.
10 points QUESTION 3 Given R=(A, B, C) is a schema and F = {2C-A AB) is a set of FDs that hold on R. Which of the following statements is not true? d=(AB. AC) is a decomposition of that is in BCNF. O Ris in 3NF O BC is a candidate key for R Ris in BCN 10 points QUESTION 4 Given R= (A. 3. CD. E) is a schema and F= (A...
Given the following relation schemas and the sets of FD's: a- R(A,B,C,D) F={ABẠC,C7D, D´A, BC+C} b- R(A,B,C,D) F={BẠC, BD, AD>B} C- R(A,B,C,D) F={AB-C, DC+D, CD+A, AD+B} d- R(A,B,C,D) F={AB=C, C+D, D™B, DE} e- R(A, B, C, D, E) F= {AB+C, DB+E, AE>B, CD+A, ECD} In each case, (i) Give all candidate keys (ii) Indicate the BCNF violation Give the minimal cover and decompose R into a collection of relations that are BCNF. Is it lossless? Does it preserve the dependencies?...
Find the decopmosition of R into R1(A, B, C), R2(B, C,D ) and
R3(C, D, E)
Let R(A,B,C,D,E) be a relation with FDs F = {AB-CDAE, C-D, D-E} The decomposition of R into R1(A, B, C), R2(B, C, D) and RP(C, D, E) is (2 Points) Select one: Lossy and Not Dependency Preserving. Lossless and Not Dependency Preserving. Lossy and Dependency Preserving. Lossless and Dependency Preserving.
Consider the schema R=(A, B, C, D, E) and let the following set F of functional dependencies hold for R: F= {A → BC, CD → E, B D } Problem 3 Suppose that the schema R=(A, B, C, D, E) is decomposed into R/ - (A, B, C) and R=(A, D, E). Show if this decomposition is a lossless decomposition with respect to the given set of functional dependencies F.
Consider the following relation R = {A,B,C,D,E} and the following set of functional dependencies F = { A → BC CD → E B → D E → A} F = { A → BC CD → E B → D E → A} Give a lossless, dependency-preserving decomposition into 3NF of schema R
5c. Consider the relation R(ABCDE) with the set of functional dependencies F={BE→D, DE→A, AD→C, B→E}. Using decomposition, find a lossless, dependency preserving, BCNF set of relations for R, if such exists. Be sure to identify the projections of the functional dependencies onto the resulting relations at each stage of the decomposition.
Choose a generic formula for combination reaction: A) A+B=C B) AB=A+B C) A+BC=AC+B D) AB+CD=AD+CB OB OA