174 ManageMent DAtAbAse For access by internal systems, information from whatever source must be put in a coherent database that can be accessed as needed. Standard database programs are used for the vast majority of information, but for information related to historical price sets used in quantitative trading, special-purpose high-performance databases are required. These databases not only capture tick data or store the data from vendors, but also play back the data in the same asynchronous pattern as when they originally occurred. This permits models to operate in a simulated environment and permits the creators to assess the model's behavior under real conditions. entitleMents Firms must be able to actively manage the individuals and applications within the firm that have access to data from various data owners. These entitlement systems permit specific devices and/or users to be turned on and off and to maintain a record of active and deactivated entitlements, which can be audited and verified by data owners.