Join conjunctive queries

Conjunctive queries where all variables are distinguished (and no variables are bound) are called equi-join queries, because they are the equivalent, in the relational calculus, of the equi-join queries in the relational algebra (when selecting all columns of the result).
In database theory, a conjunctive query is a restricted form of first-order queries using the logical conjunction operator. Many first-order queries can be  DefinitionRelationship to other query DatalogComplexity

Is a monotone query a Union of conjunctive queries?

Every monotone query is equivalent to a union of conjunctive queries, but the union may have exponentially many disjuncts. (normal form for monotone queries).
Monotone queries are precisely the queries expressible by relational calculus expressions using Æ, Ç, and ∃ only.
R 4(B,C). 2 ⋈ R 4). n be two unions of conjunctive queries.


Categories

Union of conjunctive queries
Equivalence of conjunctive queries
Evaluation of conjunctive queries
Theory of conjunctive queries
Conjunctive queries equality
Conjunctive query answering
Conjunctive query algorithm
Conjunctive conjunction examples
Contact me if you have any queries
Ovsdb-client query example
Conjunctive queries
Conjunctive query containment
Conjunctive query combine complexity
Contact us if you have any queries
Concur support contact
Request.querystring not working
Conjunctive query evaluation
Query email example
Explain responding to queries
Query escalation process