What are structural constraints in DBMS?
Cardinality Ratios and Participation Constraints taken together are called Structural Constraints.
The name constraints refer to the fact that such limitations must be imposed on the data, for the DBMS system to be consistent with the requirements.
The Structural constraints are represented by Min-Max notation..
What are the issues in physical design in DBMS?
Respondant: The main issues are how to store data from the logical model, how to group attributes from the logical design, how to organize, protect and recover files, how to structure the database for storing and connecting files, and how to design queries so as to use the most of the advantages gained by the physical .
What is design issue in DBMS?
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- Use of Entity Set vs Attributes It leads to a mistake when the user use the primary key of an entity set as an attribute of another entity set.
Instead, he should use the relationship to do so.
Also, the primary key attributes are implicit in the relationship set, but we designate it in the relationship sets.
What is the design of an ER database schema?
Fundamentally, the ER Diagram is a structural design of the database.
It acts as a framework created with specialized symbols for the purpose of defining the relationship between the database entities.
ER diagram is created based on three principal components: entities, attributes, and relationships..
What is the problem with the ER model?
A chasm trap is another problem with the ER model, which occurs when a pathway does not exist in all the related entities.
A chasm trap may exist where there are one or more relationships with a minimum multiplicity of zero forming part of the pathway between related entities..
- A chasm trap is another problem with the ER model, which occurs when a pathway does not exist in all the related entities.
A chasm trap may exist where there are one or more relationships with a minimum multiplicity of zero forming part of the pathway between related entities. - Entity Relationship Diagram – ER Diagram in DBMS.
An Entity–relationship model (ER model) describes the structure of a database with the help of a diagram, which is known as Entity Relationship Diagram (ER Diagram).
An ER model is a design or blueprint of a database that can later be implemented as a database. - Fundamentally, the ER Diagram is a structural design of the database.
It acts as a framework created with specialized symbols for the purpose of defining the relationship between the database entities.
ER diagram is created based on three principal components: entities, attributes, and relationships.
