Hierarchical grid for spatial querying

摘要: Techniques are provided for improving performance of spatial queries by defining a grid that divides the domain space into cells, and then using cell-to-item mapping to determine which items do not have be individually evaluated against location criteria queries. Based on cell an item belongs, may automatically qualify as match, disqualified, or require item-specific evaluation. To account with size, query window expanded. limit degree is expanded, plurality grids established space, where each has differently sized assigned based size items.