Project Assignment #3

Assigned: Sept 4th

Due:  Sept 28th

Before you answer the following questions, write a one-paragraph summary of what your project application domain is. In other words, remind us of your project and what you promised to do in it. Further, if we gave you comments, corrections, or suggestions about Step 2 of your project, address those modifications first before you proceed with Step 3.

1. (60 points) Use the mechanical process to convert from your E/R diagram to relations, subject to the deviations below. Do not normalize yet. Strictly follow the procedures taught in class and described in the textbook. For your solution, submit a list of relation schemas (i.e., the names of the relations and what their attributes are, and underline primary keys).
   
2. (20 points, or 40 points if your E/R diagram has no ISA hierarchy) In your conversion, deviate from the procedures discussed in class as described below. These deviations deliberately create a bad relational design so that you can use normalisation techniques in later project assignments to improve the design.
   1. Pick one many-one relationship (let us call it R) in your E/R diagram. Do not create a relation for R. Suppose R is many-one from an entity set E to an entity set F. In class, we learnt how to merge the attributes for R (and for F) into the relation for E. In this step, you should merge the attributes of the relation you would normally have created for R into the relation for F.
      
   2. Pick one many-many relation (let us call it S) in your E/R diagram between entity sets G and H. Do not create a relation for S. Merge the attributes you would normally have created in the relation for S into the relation for G or for H.
   3. Describe in words the types of problems you have introduced by deviating as instructed. Explain in terms of the attributes of the relations you have created.
   Include the relations so created in the set of relations that result from the previous step. Be sure to mark which relations you applied the deviations to with text such as "Relation for many-one relationship R resulting from deviation."
   If you do not have a many-one relationships, pick two many-many relationships to apply the deviation to. Similarily, if you do not have a many-many relationship, pick two many-one relationship to apply the deviation to. If all but one relationship are one-one, then your E/R diagram has problems we should have addressed already.
   
3. (20 points) If you have inheritance in your E/R diagram, provide two sets of relations for the entity sets in the ISA hierarchy and the relationships involving these entity sets. For one set of relations, use the E/R technique described in class for conversion. For the other set of relations, use the OO method described in class. Label each set of relations clearly with the method used for conversion. 

What to turn in: Soft copies of these answers. Attach a copy of your E/R diagram (modified and corrected based on our comments, if required) to your answer, so that we can verify that you did the conversion correctly. Identify your group by your project title and the team members. As always, note any additional constraints or restrictions that your domain poses that are not reflected in your model.