Concepts of a data base simulation language

Performance modelling of data base systems requires taking into consideration the complex interactions between the different physical design parameters and the system workload parameters. In order to facilitate a data base designer in evaluating various implementation strategies, a simulation language is presented which has three distinct components (1) data definition (2) query definition and (3) mapping to storage definition. A number of features characterize this type of descriptive mechanism. First, the system workload parameters (1 and 2) must be described in terms of statistical distributions, which implies that the storage structure is subject to the same stochastic variability. Secondly, the level of detail required to describe mappings to storage for simulation purposes is lower than that required by standard data definition or mapping languages. The process of embedding a structure in storage is decomposed into a number of steps, each introducing additional implementation oriented details.