ILOG CPLEX 11.0 User's Manual

● Cplex.DisjunctiveCutCallback in the .NET APIIn the C++ API, a query callback is installed by the method IloCplex::use.In the Java API, a query callback is installed by the method IloCplex.use.In the .NET API, a query callback is installed by the method Cplex.Use.In Callable Library applications (C API), a query callback is a user-written function installedby the routine CPXsetmipcallbackfunc, CPXsetlpcallbackfunc, orCPXsetnetcallbackfunc.Query Callbacks and Dynamic SearchQuery or diagnostic callbacks are not compatible with dynamic search, a feature whichexplores a solution space in a way that departs from a conventional branch & cut tree.Normally, ILOG CPLEX chooses whether to apply dynamic search or conventionalbranch & cut based on characteristics of the model. To benefit from dynamic search, a MIPmust not include query callbacks. In the presence of query or diagnostic callbacks,ILOG CPLEX turns off dynamic search, issues a warning, and applies conventionalbranch & cut.If you want to avoid this warning in an application where query or diagnostic callbacks arepresent, you can deliberately turn off dynamic search yourself by setting the MIP searchparameter (MIPSearch, CPX_PARAM_MIPSEARCH) to 1 (one).Query Callbacks and Deterministic Parallel SearchQuery or diagnostic callbacks are not compatible with deterministic parallel search, afeature which explores a solution space in a way that departs from a conventionalbranch & cut tree.In the presence of a query or diagnostic callback, ILOG CPLEX turns off deterministicparallel search and invokes opportunistic parallel search instead, if your application islicensed for parallel MIP optimization.For more information about deterministic and opportunistic parallel MIP optimization, seeDeterminism of Results on page 493 and Parallel MIP Optimizer on page 497.Control CallbacksControl callbacks allow you to control the branch & cut search during the optimization ofMIP problems. Because control callbacks intervene in the search, the presence of a controlcallback in an application will cause ILOG CPLEX to turn off dynamic search. Likewise,the presence of a control callback will cause ILOG CPLEX to turn off deterministicILOG CPLEX 11.0 — USER’ S MANUAL 451