Local identifiers for database objects

A method of executing database queries in a distributed database management system, the method comprising:

• receiving, by a database management system server, 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, the first operand data describing 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, a first local-to-global map comprising a first set of local identifiers relating rows at the first partition to corresponding global identifiers for the rows at the first partition;
• executing, by the database management system server, the first execution unit at the distributed database system based at least in part on the first local-to-global map;
• receiving second execution unit data describing a second execution unit, the second execution unit data comprising second operand data describing a set of operands for the second execution unit, the second operand data describing at least one operand from the first partition;
• and
• generating a second local-to-global map comprising a second set of local identifiers relating rows at the first partition to corresponding global identifiers for the rows at the first partition, the generating of the second local-to-global map comprising:
• offsetting a first local identifier of the first set of local identifiers by a first amount to generate a first local identifier of the second set of local identifiers;
• and
• offsetting a second local identifier of the second set of local identifiers by the first amount to generate a second local identifier of the second set of local identifiers;
• generating an index relating at least a portion of the rows at the first partition and at least a portion of the rows of the second partition, wherein the index is based at least in part on the first set of local identifiers;
• generating an updated index at least in part by adding a first offset difference to a first local identifier of the index, wherein the first offset difference is a difference between a partition offset for the first partition from the first set of local identifiers and a partition offset for the first partition in a second set of local identifiers;
• and
• executing the second execution unit at the distributed database system based at least in part on the updated index.

A non-transitory machine-readable medium comprising instructions stored thereon that, when executed by at least one processor, cause the at least one processor to perform operations comprising:

• receiving first execution unit data describing a first execution unit of a first database query at a distributed database system, the first execution unit data comprising first operand data describing a set of operands for the first execution unit, the first operand data describing 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 a first local-to-global map comprising a first set of local identifiers relating rows at the first partition to corresponding global identifiers for the rows at the first partition;
• executing the first execution unit based at least in part on the first local-to-global map;
• receiving second execution unit data describing a second execution unit, the second execution unit data comprising second operand data describing a set of operands for the second execution unit, the second operand data describing at least one operand from the first partition;
• generating a second local-to-global map comprising a second set of local identifiers relating rows at the first partition to corresponding global identifiers for the rows at the first partition, the generating of the second local-to-global map comprising:
• offsetting a first local identifier of the first set of local identifiers by a first amount to generate a first local identifier of the second set of local identifiers;
• and
• offsetting a second local identifier of the second set of local identifiers by the first amount to generate a second local identifier of the second set of local identifiers;
• generating an index relating at least a portion of the rows at the first partition and at least a portion of the rows of the second partition, wherein the index is based at least in part on the first set of local identifiers;
• generating an updated index at least in part by adding a first offset difference to a first local identifier of the index, wherein the first offset difference is a difference between a partition offset for the first partition from the first set of local identifiers and a partition offset for the first partition in a second set of local identifiers;
• and
• executing the second execution unit at the distributed database system based at least in part on the updated index.