A column in a relation (table) has a type. Consider implementing a date as CHAR(10) in the format YYYY-MM-DD. The lecture material states that attributes (column values) come from a domain. Using date explain the differenc between a domain and a type.

For these questions, there exists 4 relations: R(A, B,C), S(C,D), T(D,E,F), and U(B,G). The size of attributes A to D are 10 bytes each, attributes E and F have size 100 bytes, and attribute G has size 1000 bytes. The blocks size is 16,384 bytes with no spanning. Relation R has 100,000 tuples, relation S has 20,000 typles, T has 5,000 tuples, and relation U has 150,000 tuples. Other statistics: V(R,C)=10,000, V(S,D)=500, V(R,B)=1000. Assume that attributes with the same name can be joined across relations (and duplicates are eliminated during a join), and the fırst attribute is the primary key of the relation. Answer the following questions about calculating intermediate result sizes. Answer the question in terms of the # of tuples and the # of blocks. Question 3 What is the size of op=10(S)? Tuples: Blocks: Question 4 What is the size of oc>10(S)? Tuples: Blocks: Question 5 What is the size of og=5(R)? Tuples: Blocks:

Consider a relation named as BOOK that contains data about the books in a library. BOOK relation was initially created with the attributes BookID (an id that library assigns), ISBN, CopyNr (used to differentiate copies of the same book), Title, PublYear, Author, and AuthorBornYear.  Primary key: BookID, CopyNr and Author Candidate key: ISBN, CopyNr and Author Below you see dependencies of attributes:    Dependency 1 (D1): ISBN, Title, PublYear, AuthorBornYear were dependent on BookID, CopyNr and Author Dependency 2 (D2): Title and PublYear were dependent on BookID, CopyNr Dependency 3 (D3): AuthorBornYear was dependent on Author  First determine which normal form (1NF, 2NF, 3NF or BCNF) the above relation is, and why. Then, if necessary, convert the above relation to the highest normal form (BCNF). Write any assumptions that you make.

Course: Principles of Database   please solve it within 30 minutes. please please, pleaseThank you Single Choice Questions 11. Given a relation R and a condition f for selecting from relation R, the correct relational algebraic expression is (    ). A、R X R             B、 R ⋈ R        C、sf(R)                 D、 ∏f(R) 12. If relations R and S have a common attribute set Y, when executing , tuples that do not have matching values on attribute Y will be discarded. To avoid discarding those tuples, which operation should be used? (    ) A. Aggregation.                        B. Grouping. C. Outer union.                        D. Outer join. 13. To address the "lost update" problem, a transaction must obtain (    ) before updating a data set. A. Shared lock (S-lock).               B. Exclusive lock (X-lock). C. Shared lock (S-lock) and exclusive lock (X-lock). D. Shared lock (S-lock) or exclusive lock (X-lock). 14. If, during the system operation, data stored on external storage is…

For merging two relations that are not physically sorted but share an index on the characteristics in question, it is necessary to develop a hybrid merge-join method.

What is the link between the main key of a relation and the functional connections between all of its attributes?

You are given a relation R with the following attributes R(A,B,C,D,E). Assume that you were given the following functional dependencies: • FD1= AB -> E • FD2: = D -> C (a) What is a valid key for this relation? justify your response. (b) Is this relation in 3NF (Third Normal Form)? Justify your response. If it is not in 3NF, normalize the relation and demonstrate all steps of normalization.

Please explain

39 of 40 Let R = (A, B, C, D) be a relation schema with the FD's: A → B and B → A. R has how many superkeys? (Write your answer as an integer). write your answer here