1. A method for clustering a target table in a relational database management system, the method comprising: receiving a statement to define the target table; wherein the statement specifies clustering criteria; wherein the clustering criteria specifies one or more columns on which an ordering of data rows within the target table is to be based; wherein at least one of the one or more columns on which the ordering is to be based is a column of a table other than the target table; in response to receiving a command to load the data rows into the target table, ordering the data rows within the target table based on values in the one or more columns; wherein the method is performed by one or more computing devices.