25 Questions
What is the relational model based on?
Tables
In the relational model, what are the rows called?
Tuples
What is the name of the schema of a relation denoted by R(A1, A2,.An)?
Relation
What does each column in a relation have, which gives an indication of the meaning of the data items in that column?
Attribute name
In the relational model, what does each attribute have?
A domain or a set of valid values
What does the term 'domain' refer to in the context of database design?
The set of allowable values for one or more attributes
Which statement accurately describes a 'tuple' in the context of database relations?
A tuple is an ordered set of values derived from a domain
What does the term 'state' refer to in the context of relation in a database?
The populated table containing all possible column values
In database design, what does 'r(R)' represent?
A specific state (or 'value') of relation R
What is the primary role played by 'attribute name' in a domain within a relation?
It interprets the meaning of the data elements corresponding to that attribute
In the context of database design, what does 'dom(Cust-name) is varchar(25)' represent?
The maximum length of the domain of the attribute Cust-name
What is the significance of 'r(R) = {t1, t2, …, tn} where each ti is an n-tuple ti = where each vj element-of dom(Aj)' in the relational model?
It represents a specific state (or 'value' or 'population') of relation R
What does the term 'formally' imply in the statement 'Given R(A1, A2,., An) r(R) ⊂ dom (A1) X dom (A2) X.X dom(An)'?
According to the structure or principles of the relational model
What role does the attribute name play in a domain within a relation?
It designates the role played by the domain in a relation
What does 'STATE The relation state is a subset of the Cartesian product of the domains of its attributes' imply in the context of database relations?
It represents all possible combinations of values for each attribute in a relation
In the relational model, what mathematical concept is a relation based on?
Sets
What is the formal term used for the data elements in each row of a relation?
Tuples
Which paper first proposed the relational model for large shared data banks?
A Relational Model for Large Shared Data Banks
What is the attribute name called in the formal model of the relational model?
Attribute
What is the name of the schema of a relation denoted by R(A1, A2,.An)?
Relation R
In the relational model, what is the informal definition of a relation?
A set of columns representing certain facts that correspond to a real-world entity or relationship
What does the term 'domain' refer to in the context of database design?
The set of valid values for each attribute in a relation
What is the primary role played by the 'attribute name' in a domain within a relation?
Giving an indication of the meaning of the data items in a column
What does 'r(R)' represent in database design?
The formal model representing a relation as a collection of rows
What is the significance of 'r(R) = {t1, t2, …, tn} where each ti is an n-tuple ti = where each vj element-of dom(Aj)' in the relational model?
It represents the relation state as a subset of the Cartesian product of the domains of its attributes
Test your knowledge of the relational data model concepts with this quiz based on Lecture 3. Explore the informal definitions and key ideas of the relational model proposed by Dr. E.F. Codd in 1970.
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