COLLECTION OF STATISTICS FOR SPATIAL COLUMNS OR R-TREE INDEXES

摘要

Techniques for collecting statistics of column data or R-Tree indexes are provided. A distributed database system includes a plurality of processing nodes controlling portions of spatial data. The nodes are instructed to create minimum bounding rectangles (MBR's) for their spatial data or R-Trees. The individual MBR's are merged and reformatted into a grid of equally sized cells. Each processing node is provided a copy of the grid to update based on statistics of each processing node's spatial data for a target table. The updated grids are then merged into a single grid and used by an optimizer to evaluate queries before the queries are executed.