1. A method of generating a datamart having aggregates using a computer system, the method comprising: accessing a schema definition which describes a schema for the datamart; accessing a description of a set of aggregates to be generated in the datamart; generating a set of commands from the schema definition, including, generating a set of table creation commands, and generating a set of table access and manipulation commands, the set of table access and manipulation commands corresponding to the semantic meaning of the schema; generating a set of generate aggregates commands; and generating a set of aggregate tables using the set of generate aggregates commands.