Podcast
Questions and Answers
What is the primary function of the SELECT operation in relational algebra?
What is the primary function of the SELECT operation in relational algebra?
- To add new columns to a relation
- To combine two relations into a single relation
- To select a subset of tuples from a relation based on a condition (correct)
- To eliminate duplicate tuples from a relation
What is the result of the PROJECT operation in relational algebra?
What is the result of the PROJECT operation in relational algebra?
- A set of distinct tuples with selected columns (correct)
- A relation with all columns and duplicate tuples
- A multiset of tuples with duplicate columns
- A relation with all columns and no duplicate tuples
What is the property of the SELECT operation that allows multiple operations to be combined into a single operation?
What is the property of the SELECT operation that allows multiple operations to be combined into a single operation?
- Associativity
- Commutativity (correct)
- Selectivity
- Distributivity
What is the term used to describe the fraction of tuples selected by a selection condition in relational algebra?
What is the term used to describe the fraction of tuples selected by a selection condition in relational algebra?
What is the purpose of relational algebra in the relational model?
What is the purpose of relational algebra in the relational model?
What is the term used to describe a sequence of relational algebra operations?
What is the term used to describe a sequence of relational algebra operations?
The PROJECT operation is commutative.
The PROJECT operation is commutative.
The SELECT operation can be used to deselect columns from a table.
The SELECT operation can be used to deselect columns from a table.
A relational algebra expression can consist of a sequence of unary and binary operations.
A relational algebra expression can consist of a sequence of unary and binary operations.
The term 'degree' refers to the number of tuples in a relation.
The term 'degree' refers to the number of tuples in a relation.
The DIVISION operation is a unary relational operation.
The DIVISION operation is a unary relational operation.
Relational algebra provides a basic set of operations for the relational model.
Relational algebra provides a basic set of operations for the relational model.
