Patent ID: 7203686

Claim:
A computer-implemented method of performing a join in a partitioned database system, the method comprising: identifying a join that identifies a right table and a left table, the right table including a plurality of right table rows, each of the plurality of right table rows grouped into one of a plurality of right table partitions, the left table including one or more left table rows; determining that a partitioning column of the right table is specified in an equality condition of the join; preparing the left table for joining one or more rows of the left table with one or more rows of the right table, wherein preparing the left table comprises: selecting one of the plurality of left table rows; and generating a partition number for the selected one of the plurality of left table rows; for a left table row for which a partition number was generated: identifying a right table partition with a partition number that matches the generated partition number; and joining, using a product join, the one or more right table rows in the matching partition with the selected one of the left table rows in response to determining that one or more join conditions are satisfied.