1. A method of processing a database query from a client in a client-server database management system, the method comprising: receiving a database query from a client; responding to the database query by returning to the client only a subset of the data requested by the client in the database query based upon a usage statistic associated with the database query such that less than all of the data requested by the client in the database query is returned to the client in response to the database query, wherein the usage statistic is based upon automatically tracked usage data that is indicative of how data requested by the client is used by the client; and during a current or prior execution of the database query, generating the usage statistic by automatically tracking the usage of data returned in response to the database query during the current or prior execution of the database query to identify data from among the data returned in response to the database query that is unlikely to use, wherein the subset of data excludes data identified during automatic tracking as being unlikely to use.