1. An apparatus comprising: a processor component; a communications component for execution by the processor component to receive computer-executable query instructions to solve a mixed-integer linear programming (MILP) problem, wherein the query instructions comprise: a first expression that conveys an objective function and at least one side constraint of the MILP problem, wherein the objective function and the at least one side constraint define a master problem of the MILP problem; a second expression that conveys a first mapping of data values of graph data associated with the MILP problem to a first graph; and a third expression that conveys a selection of a first graph-based algorithm to solve a first subproblem of the MILP problem based on the first graph; a subproblem component for execution by the processor component to replace the third expression in the query instructions with a fourth expression as part of a decomposition of the MILP problem, the fourth expression comprising instructions to implement the first graph-based algorithm to solve the first subproblem; and an execution control component for execution by the processor component to perform an iteration of solving the MILP problem, wherein performing the iteration comprises: executing the first expression to derive a solution to the master problem; and executing the fourth expression to derive a solution to the first subproblem based on the first mapping and the solution to the master problem.