Derived attributes cannot be directly represented in the relational data model. Instead, they are represented as methods.

The primary key of the representation of a weak entity set consists of the primary key of the strong entity set and the discriminator of the weak entity set.

For a binary one to one relationship, the primary key of either one of the participating entity sets becomes the prime attribute.

For schemas derived from strong entity sets, the primary key of the entity set serves as the primary key of the resulting schema. This is because the primary keys are to be preserved as they are unique.

We can create foreign key constraints on relational schema derived from ER diagram and also it is possible to derive relational schema from ER diagrams.

For a binary many to many relationship, the primary key on the many side of the participating entity sets becomes the prime attribute.

For a binary many to many relationship, the union of the primary keys of the participating entity sets becomes the prime attribute.

For a binary many to many relationship, the union of the primary keys of the participating entity sets becomes the prime attribute.

The schema for the relationship set linking a weak entity set to its corresponding strong entity set is redundant and it need not be present in the relational database design derived from an ER diagram.

The cardinality ratio of a relationship can affect the placement of relationship attributes. The placement of the relationship attributes are not dependent on the alphabetical orderor the data in the attribute.