1. A method of managing a grid computing environment comprising a plurality of resources, said method including steps of: determining currently executing and scheduled job portions having particular characteristics for said plurality of resources; performing job portions of a data processing request using respective heterogeneous and distributed resources of said grid computing environment, said resources including a plurality of platforms having different implementations, semantic behaviors and application programming interfaces and which may exhibit different performance for a given portion of a given job; periodically capturing and storing as data records, in correspondence with a plurality of characteristics of a respective job portion, a snapshot of current instantaneous operations of individual application environments in said grid computing environment from said respective resources performing said job portions of said data processing request in content-addressable storage, said data records corresponding to performance of respective ones of said respective resources while processing respective ones of said job portions, said performance being monitored in correspondence with said characteristics of respective ones of said job portions wherein said plurality of characteristics include nature of processing being performed during said instantaneous operation, said platform on which said processing is performed, said resource or resources on which said processing is performed and concurrent processing in said grid environment, such that any performance data or other parameter of said data records for respective ones of said resources may be retrieved based on any other performance data or parameter of said data records or logical combination thereof with arbitrarily fine granularity to closely match characteristics of job portions of any other job to assess impact of said other job on said grid environment, determine allocation of said resources to said portions of said other job or predict performance of said other job as performed on available resources; storing actual performance and predicted performance of said other job as performed by ones of said resources allocated to said other job; selecting data records in accordance with one or more of said plurality of characteristics stored in said data records as selected data records; retrieving said selected data records; and processing data retrieved in said retrieving step to produce processed performance data as historical performance statistics corresponding to said characteristics of said job portions and said resources.