Spatial Data Management 2021/8/25
2021/8/25 1 Spatial Data Management
Outline Introduction of Spatial data Spatial Query Language Spatial Index structures Spatial Query Process and Optimization 2021/8/25
2021/8/25 2 Outline ◼ Introduction of Spatial data ◼ Spatial Query Language ◼ Spatial Index Structures ◼ Spatial Query Process and Optimization
Introduction of St atial data 2021/8/25
2021/8/25 3 Introduction of Spatial data
Types of spatial data Point data a Points in a multidimensional space Used when shape is not relevant (eg to represent location of detector when scale is small o E.g., Raster data such as satellite imagery, where each pixel stores a measured value o E.g., Feature vectors extracted from text 2021/8/25
2021/8/25 4 Types of Spatial Data ◼ Point Data ❑ Points in a multidimensional space ◼ Used when shape is not relevant (eg to represent location of detector) ◼ when scale is small ❑ E.g., Raster data such as satellite imagery, where each pixel stores a measured value ❑ E.g., Feature vectors extracted from text
Types of spatial data Polyline Data o A finite set of straight line segments such that each segment endpoint (called a vertex) is shared by exactly two segments, except that it may optionally have two endpoints(called the extreme points), which belong to only one segment a Polylines are classed as simple, non-simple or closed a) Simple polyline b)non-simple polyline c)closed polyline 2021/8/25
2021/8/25 5 Types of Spatial Data ◼ Polyline Data ❑ A finite set of straight line segments such that each segment endpoint (called a vertex) is shared by exactly two segments, except that it may optionally have two endpoints (called the extreme points), which belong to only one segment. ❑ Polylines are classed as simple, non-simple or closed. a) Simple polyline b) non-simple polyline c) closed polyline