Database concepts and design questions.

Define the following terms in brief

1. Database
2. Database Management System (DBMS)
3. Data redundancy
4. Database administrator
5. Data integrity

Use the diagrams below to answer the following questions.

1. Give the name of each of the following database models.
2. If you are designing a database , which one will you choose and why ? (Give three reasons)

During the database design process one of the main activities in the phase of analysis is how to deal with user view especially if there is need of more than one user view for a certain database. There are three main approaches to managing the requirements of a database system with multiple users. Use the diagram below to answer the following questions.

1. Provide the name of the approach represented in each diagram.
2. Give two differences between the approaches you have provided.

Database involves a series of phases which are used in designing process. The phases involve planning , analysis, dabase design, implementation and maintenance.

1. During database phase how do you know if the database is complex (answer in short)
2. If it is complex which approach will you use during the design phase ?

One of the most difficult aspects of database design is the fact that designers, programmers, and end-users tend to view data and it`s use in different ways. To ensure that we get a precise understanding of hte nature of the data and how it is used by the enterprise, we need to have a model for communication that is non-technical and free of ambiguities. The entity-Relationship (ER) model is one such example.

Draw Entity Relationship model diagram of the following case study. Show only entities, attributes, relationship and primary keyof each entity.
This is the summary from the customer. "[...] we have[..] video tapes that we need to keep track of. A tape is the one hold movies. Each of our video tapes has a tape number. For each movie we need to know it's title and category, director and year. We do have multiple copies of many of our movies. We give each movie a specific id, and then track which movie a tape contains. A tape belongs to a format. A tape may be either Beta or VHS format. We always at least one tape for each movie we track, and each tape is always a copy of a single, specific movie. Our tapes are adapted to the movie lengths, so we don`t have any movies which require multiple tapes. The movies are stored on shelf according to their category sorted by movie title. We are frequently asked for movies starring specific actors. [..] The actor plays the movie. Customers like to know each actor`s real birth, name and age. We keep track only actors that appear in movies in our inventory. [......] Rentals are for one or more days, each movie with an individual price per day. Furthermore , we additionally charge 1$ per beta format tape , 2$ for DVD and another $ for movies longer than 2 hours. "

Describe the following terms

• Functional dependency
• Normalization
• Database schema
• First Normal Form (1NF)
• Entityy integrity