1. A computer-implemented method to provide a feedback loop between query optimization and cache management, the method comprising: monitoring access to at least a data object stored in a database having a database cache stored in memory; determining a memory residency priority for keeping the data object pinned in the database cache, based on the monitored access to the data object; determining, by operation of one or more computer processors, a respective cost of executing each of a plurality of access plans generated from a query configured to access the data object, wherein each cost is determined based on the memory residency priority for keeping the data object pinned in the database cache, whereby the feedback loop is provided between query optimization, defined by determination of the respective cost of executing each access plan, and cache management defined by determination of the memory residency priority; and executing an access plan selected from the plurality of access plans, wherein access patterns associated with executing the access plan are tracked.