Database and IT project managment

Example

• 1. Local College recruits both full time and part-time staff. How will you illustrate this scenario using a specialization hierarchy (include some sample attributes).

2. From your understanding and reading of the lecture notes what is the difference between partial and total completeness. Illustrate with examples.

Before explaining the differences between partial and total completeness. I conducted additional research on the subject. Entities within the data models often times relate to attributes. Completeness constraint means an entity supertype (type of entity that relates to one or more unique attribute) that occur relates to at least 1 subtype or subgroup of the supertype. 

Partial completeness which is represented by a cirlce and one line- not every type of entity that relates to 1 or more subgroups occur as one of the member subgroups. Not all entity types will have relation. 

Ex:  

Total completeness is represented by a circle and 2 lines; every entity type must relate to at least 1 subgroup/subtype

Ex: