An organization undertakes manufacturing projects. There are
different kinds of employees (full time and part time). Each
employee can move on one or more projects. Each project is
undertaken on the request of a client. A client can be a public sector
company or a private sector company. A project can use a number of
items from a different manufacturers and an item may be used by
several projects. Clearly indicate the entities, attributes, relationship
between entities, keys and cardinalities and make suitable
assumptions.
(a) Draw the EER (extended ER) diagram for the above organization showing all entities , relationship, aggregation, generalization /specialization and convert it into relational schemas
(b) Draw the appropriate tables and relationship among the tables for the above diagram and normalize the tables up to 3NF
(c) Identify weak entity sets in the above diagram if any. How will you convert a weak entity set to a strong entity set? Illustrate.
(d) Identify multivalued dependency in the above diagram.
(e) Using the manufacturing example, write relational – algebra expressions to do the the following queries:
• Find out how many employees working on P1 and P2 projects
• How many projects are using items I1 and I2.
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