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May 5, 2015 · From the above definitions, apart from the number of elements in either sets, it seems that a prime attribute and a subset of a candidate key are pretty much the same. Both of these terms are being brought up simultaneously while explaining Third Normal Form and Transitive Dependencies, which is confusing me.
Jan 26, 2016 · All the other attributes are non-prime attributes. Again, here HI is a composite candidate key and both H and I are key attributes together forming the primary key. All other attributes are dependent on HI together, else it will result in partial function dependency (PFD) or, in other words, the criteria for 2nd Normal Form won't be satisfied.
Oct 16, 2021 · Relation is R(P,Q,C,A,B) R has the following functional dependencies: F = { P→QC , CA→B , Q→A , B→P } What are the prime attributes
Jul 28, 2019 · I have been studying DBMS ans I have a question that I got conflicting answers to: Is prime attribute that is dependant on another prime attribute allowed under BCNF? Meaning P->P. I know that NP->P is not allowed. and also NP->NP (as it is not 3NF - transitive relation) Thanks.
Mar 8, 2020 · Every non-prime attribute of R is non-transitively dependent on every key of R. There are no non-prime attributes, thus 3NF is satisfied. The criteria for 2NF is: 1NF. Every non-prime attribute is (...) Again, there are no non-prime attributes. Is this true generally?
Jul 20, 2014 · A superkey of a table T is a set of columns that functionally determines every attribute. A candidate key (CK) is a superkey that contains no smaller superkey. We can pick one CK as primary key (PK) and then call the other CKs alternate keys. A column is prime when it is in some CK.
Feb 20, 2023 · ANSWER: CDE is prime because C,D and E are individually prime. If the attributes of a group are prime, then the group is also prime (the group does not have to be part of a candidate key as a whole). Share
Oct 23, 2016 · If in a relation schema a non prime attribute depends from another non prime attribute we can only say that this dependency does not violates the original Codd’s definition, that requires only that every non prime attribute must be “fully dependent on each candidate key of R”, which can also be expressed as: does not exists a dependency in which the left part is a proper subset of a candidate key and the right part is a non prime attribute.
Every non-prime attribute of R is non-transitively dependent on every key of R. From the book Database Systems The Complete Book 2nd Edition, key means candidate key. And I got the definition of transitive dependent here.
Apr 30, 2016 · According to 3NF, Any non-trivial functional dependency X-> A shouldn't exist unless X is a super key or A is a prime attribute (Where as the BCNF doesn't allow the latter). Is there a reason for this?
