enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Tuple relational calculus - Wikipedia

    en.wikipedia.org/wiki/Tuple_relational_calculus

    The formal semantics of such atoms is defined given a database db over S and a tuple variable binding val : V → T D that maps tuple variables to tuples over the domain in S: v.a = w.b is true if and only if val(v)(a) = val(w)(b) v.a = k is true if and only if val(v)(a) = k; r(v) is true if and only if val(v) is in db(r)

  3. Consistency (database systems) - Wikipedia

    en.wikipedia.org/wiki/Consistency_(database_systems)

    The CAP theorem is based on three trade-offs, one of which is "atomic consistency" (shortened to "consistency" for the acronym), about which the authors note, "Discussing atomic consistency is somewhat different than talking about an ACID database, as database consistency refers to transactions, while atomic consistency refers only to a property of a single request/response operation sequence.

  4. Check constraint - Wikipedia

    en.wikipedia.org/wiki/Check_constraint

    A check constraint is a type of integrity constraint in SQL which specifies a requirement that must be met by each row in a database table. The constraint must be a predicate . It can refer to a single column, or multiple columns of the table.

  5. Free variables and bound variables - Wikipedia

    en.wikipedia.org/wiki/Free_variables_and_bound...

    Variable binding relates three things: a variable v, a location a for that variable in an expression and a non-leaf node n of the form Q(v, P). Note: we define a location in an expression as a leaf node in the syntax tree. Variable binding occurs when that location is below the node n. In the lambda calculus, x is a bound variable in the term M ...

  6. Constraint (mathematics) - Wikipedia

    en.wikipedia.org/wiki/Constraint_(mathematics)

    If an inequality constraint holds as a strict inequality at the optimal point (that is, does not hold with equality), the constraint is said to be non-binding, as the point could be varied in the direction of the constraint, although it would not be optimal to do so. Under certain conditions, as for example in convex optimization, if a ...

  7. Slack variable - Wikipedia

    en.wikipedia.org/wiki/Slack_variable

    If a slack variable is positive at a particular candidate solution, the constraint is non-binding there, as the constraint does not restrict the possible changes from that point. If a slack variable is negative at some point, the point is infeasible (not allowed), as it does not satisfy the constraint. Slack variables are also used in the Big M ...

  8. Non-binding constraint - Wikipedia

    en.wikipedia.org/?title=Non-binding_constraint&...

    Pages for logged out editors learn more. Contributions; Talk; Non-binding constraint

  9. Non-binding - Wikipedia

    en.wikipedia.org/wiki/Non-binding

    Non-binding or nonbinding may refer to Nonbinding allocation of responsibility (NBAR) in a superfund; Non-binding authority in law; Non-binding arbitration; Non-binding constraint, mathematics; Non-binding opinion in patent law: International preliminary report on patentability objective; Non-binding opinion (United Kingdom patent law) Non ...