In the theory of relational databases, a Boolean conjunctive query is a conjunctive query is a tuple is equal to the arity. Such a query evaluates to either true or false depending on whether the relations in the database contain the appropriate tuples of values, i.e. the conjunction is valid according to the facts in the database.

As an example, if a database schema contains the relation symbols (binary, who's the father of whom) and . This query evaluates to true if there exists an individual who is a child of Mark and employed. In other words, this query expresses the question: "does Mark have an employed child?"

Complexity

See also

• Logical conjunction

• Conjunctive query

References