1. An application server computer program product for accessing a database, said application server providing database access functions for one or more applications, comprising: a plurality of computer-executable instructions recorded on tangible computer-readable media, wherein said instructions, when executed by at least one computer system, cause the at least one computer system to perform the steps of: maintaining historical data concerning data from said database required by said one or more applications, said database having at least one database table, each database table of said database defined by a respective set of fields and containing a respective plurality of entries, each entry having respective data in the set of fields defining the respective database table; receiving data requests from said one or more applications, said data requests requesting data contained in said database, said data requests conforming to a common database-independent interface; and responsive to at least some of said data requests, generating a respective request to access said database, each said request to access said database identifying a respective subset of one or more fields defining at least one database table of said database to be returned responsive to the request; wherein, for at least some said requests to access said database, said respective subset contains at least one and fewer than all the fields defining a first database table of said database; wherein each said respective subset of one or more fields of said database is determined by said application server using data of said historical data other than the data request responsive to which the respective subset is generated.