There are two alternative methods of representing an employee’s optional (single) phone number.  The first is to use a nullable attribute and the second is to use a weak entity.  1. Given a requirement that a large number of the employees (> 80%) are assigned a phone number, which is the preferred method and why?  2. Given a requirement that only a small number of employees (< 10%) are assigned phone numbers, which is the preferred method and why?  3. How would the requirement of ‘multiple phone numbers can be assigned to an Employee’ affect your decision?  Your answers should consider the performance tradeoff between number of database operations per query and record’s size.

Draw an ERD for the following situation. Artwork is generated by an artist, denoted as 0:1 (0 for an unknown artist). An alternative approach could involve having a valid artist instance with the name "Unknown." This modification would allow the enforcement of a business rule stating that every artwork piece must be associated with an artist stored in the database. Consequently, the cardinality near the artist entity in the diagram would change to a mandatory 1. The Item Status attribute of artwork enables the categorization of artwork as Display (requiring a valid value for the Item Museum Location attribute), Storage, Loan, or Shows. Artwork items can be featured in a show; however, the current entity-relationship diagram (ERD) does not provide a mechanism to indicate that an artwork item cannot be part of two shows with overlapping dates. This business constraint will need to be documented as part of the system design.

PLZ help with the following: Create a Crow’s Foot ERD. Draw YOUR entity relationship diagram (ERD) to indicate entities, relationships, connectives, and resolve M:N relationships. For the following: The faculty and students (we refer to them in our system as clients) can electronically check out any book at any time. A book must have at least one author but can have more authors. An author must have written at least one book or more to be included in the system. A book may have neverbeen checked out, but can be checked out many times by the same client or different clients over time. A client may have never checked out a book or they may have checked out many books over time. To simplify determining which client currently has a given book checked out, a M:N relationship between BOOK and CLIENT should be maintained. The information recorded for each book is book number, book title, book subject, and year of publication.   For each author, the library records the author ID,…

Consider the following dimensions, dimension attributes, and dimension sizes for Farm Coop-Insurance: Member(member_ID, Name, Address). On average, there are two members for each policy and item covered by the policy. InsuredItem(Item_ID, Description, Coverage_Type). There is an average of ten covered items per policy. CoopOffice(Office_ID, Address, Manager_name). Each policy is registered and managed by only one office of the cooperative. Policy(Policy_ID, Type). The company has approximately one million policies at the present time. Approximately five percent of these policies experience some change each month. Period(Date_Key, Fiscal_Period). The length of the fiscal period is one month. The decision system reports are supposed to be based on five years of data. Claim(Claim_ID, Claim_Description, Claim_Type). The facts to be recorded for each combination of these dimensions are Policy_Premium, Deductible, and Monthly_Claim_Total. Design a star schema for this problem.  Using the…