ompare their advantages and sadvantages. ease briefly describe the fference between Entity Flow hart (EFC) and Activity Circle agram and their respective haracteristics.

A weak entity type is what? The secret? Give an instance: A specialization of attributes?What does the ER diagram represent? Diagram and example

There are two UML diagrams types for describing dynamic models: StateChart diagrams and Interaction diagrams. Let’s focus on interaction diagrams. Interactions diagrams can be categorized into two types: Communication diagram and sequence diagram. Let’s reduce our focus on the sequence diagram. The structure of the sequence diagram helps us to determine how decentralized the system is. We distinguish two structures for sequence diagrams. What are those two structures (or diagrams)? And when do we choose each structure?

A weak entity set can always be made into a strong entity set by adding to its attributes the primary-key attributes of its identifying entity set. Outline what sort of redundancy will result if we do so.