1. A method of updating a record in a database system in conjunction with one or more transactions involving at least a portion of the record, the method comprising the steps of: determining a record affected by a given one of the transactions; retrieving a current version of the record from a memory of the system; estimating at least one of a transaction rate and a period probability for the record using an event-driven estimator based at least in part on application of at least a portion of a stochastic model of time-dependent behavior to the current version of the record, the model having associated therewith a plurality of periods and a number of period-based transaction rates; and generating an updated version of the record based on the event-driven estimator.