Managing and querying spatial point data in column stores

1. A method comprising:

receiving, at a database comprising a columnar data store storing data in a column-oriented structure, a query on a spatial data set occupying a multi-dimensional space;

mapping, by at least one data processor, the spatial data set to physical storage in the database, the spatial data set having a plurality of coordinate values that are encoded using a corresponding plurality of value identifiers, the mapping using a space-filling curve having a minimal order such that the space-filling curve traverses every cell in a grid divided into a minimum quantity of cells, the minimal order of the space-filling curve being determined based at least on a quantity of the plurality of value identifiers used to encode the plurality of coordinate values, the mapping of the spatial data set using the space-filling curve having the minimal order transforming the spatial data set from the multi-dimensional space to a one-dimensional space along the space-filling curve, and the spatial data set being mapped using the space-filling curve having the minimal order such that no two points in the spatial data set are mapped to a same distance on the space-filling curve;

compacting, by the at least one data processor, the spatial data set based at least on the mapping of the spatial data set using the space-filling curve having the minimal order; and

executing, by the at least one data processor, the query by at least retrieving, from the database, at least a portion of the compacted spatial data set responsive to the query.

2. The method as in claim 1 , wherein the space-filling curve comprises a Hilbert curve.

3. The method as in claim 2 , wherein the mapping comprises:

transforming, by at least one data processor, points in the spatial data set into a positive coordinate space; and

defining, by at least one data processor, a quadrant based on boundaries of the transformed points.

4. The method as in claim 3 , wherein the mapping further comprises:

determining, by the least one data processor, the minimal order for the Hilbert curve.

5. The method as in claim 1 , wherein the minimal order further provides that points in the spatial data set have different respective distances on the space-filling curve, and wherein the respective distances vary based at least on a relative spatial proximity between the points in the spatial data set.

6. The method as in claim 1 , wherein the mapping further comprises:

sorting, by the at least one data processor, the points in the spatial data set, the points in the spatial data set being sorted according to a respective distance on the space-filling curve.

7. The method as in claim 6 , wherein the mapping further comprises:

generating, by the at least one data processor, a data dictionary and a corresponding bit compressed vector for each axis of the spatial data set.

8. The method as in claim 1 , wherein the spatial data set is compressed such that no two points in the spatial data set have a same distance on the space-filling curve.

9. The method as in claim 1 , wherein the using of the space-filling curve having the minimal order prevents gaps between points mapped to the space-filling curve.

10. The method as in claim 1 , wherein the space-filling curve comprises a Z-curve or a Moore curve.

11. The method as in claim 1 , wherein the minimal order corresponds to a number of bits required to represent every one of the plurality of value identifiers.

12. A non-transitory computer program product storing instructions which, when executed by at data processor of at least one computing system, result in operations comprising:

receiving, at a database comprising a columnar data store storing data in a column-oriented structure, a query on a spatial data set occupying a multi-dimensional space;

mapping, by at least one data processor, the spatial data set to physical storage in the database, the spatial data set having a plurality of coordinate values that are encoded using a corresponding plurality of value identifiers, the mapping using a space-filling curve having a minimal order such that the space-filling curve traverses every cell in a grid divided into a minimum quantity of cells, the minimal order of the space-filling curve being determined based at least on a quantity of the plurality of value identifiers used to encode the plurality of coordinate values, the mapping of the spatial data set using the space-filling curve having the minimal order transforming the spatial data set from the multi-dimensional space to a one-dimensional space along the space-filling curve, and the spatial data set being mapped using the space-filling curve having the minimal order such that no two points in the spatial data set are mapped to a same distance on the space-filling curve;

compacting, by the at least one data processor, the spatial data set based at least on the mapping of the spatial data set using the space-filling curve having the minimal order; and

executing, by the at least one data processor, the query by at least retrieving, from the database, at least a portion of the compacted spatial data set responsive to the query.

13. The computer program product as in claim 12 , wherein the space-filling curve comprises a Hilbert curve.

14. The computer program product as in claim 13 , wherein the mapping comprises:

transforming points in the spatial data set into a positive coordinate space; and

defining a quadrant based on boundaries of the transformed points.

15. The computer program product as in claim 14 , wherein the mapping further comprises:

determining the minimal order for the Hilbert curve.

16. The computer program product as in claim 12 , wherein the minimal order further provides that points in the spatial data set have different respective distances on the space-filling curve, and wherein the respective distances vary based at least on a relative spatial proximity between the points in the spatial data se.

17. The computer program product as in claim 12 , wherein the mapping further comprises:

sorting the points in the spatial data set, the points in the spatial data set being sorted according to respective distances of the points on the space-filling curve.

18. The computer program product as in claim 17 , wherein the mapping further comprises:

generating a data dictionary and a corresponding bit compressed vector for each axis of the spatial data set.

19. The computer program product as in claim 12 , wherein the using of the space-filling curve having the minimal order prevents gaps between points mapped to the space-filling curve.

20. The computer program product as in claim 12 , wherein the space-filling curve comprises a Z-curve or a Moore curve.

21. A system comprising:

computer hardware comprising at least one data processor; and

a database comprising a columnar data store storing data in a column-oriented structure;

wherein the computer hardware performs database operations comprising:

receiving a query on a spatial data set occupying a multi-dimensional space;

mapping the spatial data set to physical storage in the database, the spatial data set having a plurality of coordinate values that are encoded using a corresponding plurality of value identifiers, the mapping using a space-filling curve having a minimal order such that the space-filling curve traverses every cell in a grid divided into a minimum quantity of cells, the minimal order of the space-filling curve being determined based at least on a quantity of the plurality of value identifiers used to encode the plurality of coordinate values, the mapping of the spatial data set using the space-filling curve having the minimal order transforming the spatial data set from the multi-dimensional space to a one-dimensional space along the space-filling curve, and the spatial data set being mapped using the space-filling curve having the minimal order such that no two points in the spatial data set are mapped to a same distance on the space-filling curve;

compacting the spatial data set based at least on the mapping of the spatial data set using the space-filling curve having the minimal order; and

executing the query by at least retrieving from the database, at least a portion of the compacted spatial data set responsive to the query.