A control method for performing a multi-table join operation and a corresponding apparatus are disclosed. Fields in a table whose fields participating in a theta join operation and used in the query statement meet a first preset condition are decomposed, to obtain a plurality of first field groups, so that the theta join operation can be implemented in steps in a form of the plurality of field groups. This can reduce a data amount of Cartesian product calculation during one join operation, greatly reduce network transmission overheads, computing overheads, and memory overheads, and improve execution efficiency.