costbased

Cost-based is an adjective used to describe methods that rely on estimated costs to guide decisions or actions. Often written cost-based, it appears in fields such as database systems, operations research, and optimization. The emphasis is on quantifying trade-offs via cost models.

Cost-based optimization (CBO) in database management selects query execution plans by estimating costs of different strategies. Cost models consider I/O, CPU, memory, and parallelism; statistics such as row counts guide estimations. The planner compares alternatives and chooses the lowest-cost plan. CBO's effectiveness hinges on accurate statistics and a robust model, and it may require statistics maintenance and tuning.

In other areas, cost-based approaches influence pricing, scheduling, and resource allocation. Cost-based pricing adds a cost-based markup to cover production and distribution expenses. In machine learning, cost-based methods optimize loss functions; in operations research, cost-based models help allocate limited resources and sequence tasks.

Limitations include sensitivity to incorrect cost assumptions, changing workloads, and model complexity. The term is sometimes used broadly, and care is needed to specify the cost model and its assumptions.