Entities:

User

Property

Message

Search

Relationships:

User

Activity tasks:

Perform detailed conceptual design:

Your task is to derive a detailed conceptual design considering only the high$-$priority refined stories highlighted above. As part of this, you must consider the data$/$database needs associated with the stories $($i$.$e$.,$ you can ignore things that are not relevant to data$/$database aspects$)$ and do the following:

Concretize the list of entities relevant to the stories being considered. For each entity, identify attributes and determine their types $($i$.$e$.,$ simple $/$ composite, singlevalued $/$ multi$-$valued, stored $/$ derived$).$ Only discuss and include entities$/$attributes relevant to the stories being considered.

Identify the primary key for each entity above. Provide a one$-$line justification for your primary key.

Concretize relationships among the entities identified above. For each relationship, identify cardinality and participation constraints. Once again, only discuss relationships relevant to the stories being considered.

Note:

Ensure that entity$/$attribute$/$relationship names are meaningful; create and consistently use a uniform naming convention.

If you make any assumptions related to a story, state it explicitly.

Example format:

Use the format shown in this example to represent your $($partial$)$ conceptual design $($primary key is underlined$)$:

Entity: Employee

Attributes:

$\backslash$table$[[$ssn$],[$name $[$composite$]],[$last name$],[$first name$],[$date of birth$],[$age $[$derived$]],[$address $[$composite$,$ multi$-$valued$]],[$address line $1],[$address line $2],[$city$],[$state$],[$zip code$]]$

Example format:

Use the format shown in this example to represent your $($partial$)$ conceptual design $($primary key is underlined$)$:

Entity: Employee

Attributes:

$\backslash$table$[[$ssn$],[$name $[$composite$]],[$last name$],[$first name$],[$date of birth$],[$age $[$derived$]],[$address $[$composite$,$ multi$-$valued$]],[$address line $1],[$address line $2],[$city$],[$state$],[$zip code$],[$annual$\_$salary$]]$

Primary key justification: ssn is unique for everyone, so it is a good primary key.

Entity: Dependent

Attributes:

$\backslash$table$[[$ssn$],[$name$],[$Relationship$]]$

Primary key justification: ssn is unique for everyone, so it is a good primary key.

Entity: Department

Attributes:

name

building $[$multi$-$valued$]$

Primary key justification: Department name is assumed to be unique within a company.

Relationship: Employee has Dependent

Cardinality: One to many