A database management system server of a distributed database system , the database management system server comprising a processor and memory in communication with the processor, wherein the database management system server is programmed to perform operations comprising: receiving first execution unit data describing a first execution unit of a first database query, the first execution unit data comprising first operand data describing a set of operands for the first execution unit, wherein each execution unit is any discrete database operation, wherein execution unit data describes a respective execution unit, wherein each of the operands includes one or more rows from one or more partitions managed by the database management system server that are to be operated on to perform a respective execution unit; determining, by the database management system server , that the first operand data describes at least one operand from a first partition of the distributed database system and at least one operand from a second partition of the distributed database system; generating, by the database management system server , after receiving the first execution unit data, a first set of local identifiers describing rows at the first partition , wherein the first set of local identifiers describing rows at the first partition is drawn from a continuous range of values for the first partition and the first execution unit; generating, by the database management system server , after receiving the first execution unit data, a first set of local identifiers describing rows at the second partition , wherein the first set of local identifiers describing rows at the second partition is drawn from a continuous range of values for the second partition and the first execution unit; and executing the first execution unit at the distributed database system based on the first set of local identifiers describing rows at the first partition and the first set of local identifiers describing rows at the second partition . receiving first execution unit data describing a first execution unit of a first database query, the first execution unit data comprising first operand data describing a set of operands for the first execution unit, wherein each execution unit is any discrete database operation, wherein execution unit data describes a respective execution unit, wherein each of the operands includes one or more rows from one or more partitions managed by the database management system server that are to be operated on to perform a respective execution unit; determining, by the database management system server , that the first operand data describes at least one operand from a first partition of the distributed database system and at least one operand from a second partition of the distributed database system; generating, by the database management system server , after receiving the first execution unit data, a first set of local identifiers describing rows at the first partition , wherein the first set of local identifiers describing rows at the first partition is drawn from a continuous range of values for the first partition and the first execution unit; generating, by the database management system server , after receiving the first execution unit data, a first set of local identifiers describing rows at the second partition , wherein the first set of local identifiers describing rows at the second partition is drawn from a continuous range of values for the second partition and the first execution unit; and executing the first execution unit at the distributed database system based on the first set of local identifiers describing rows at the first partition and the first set of local identifiers describing rows at the second partition . <EOS>