Modelling the world

SQL Server Spatial Indexes

Spatial Data in SQL Server has special indexing because it has to perform specialised functions. It is able, for example, to break down an indexed space into a grid hierarchy by using a technique called tessellation. This is a rules-based system that, when you compare a shape to an index, works out how many cells in the the grid hierarchy are touched by that shape , and how deep down the grid hierarchy to search. There is powerful magic in Spatial Indexes as Surenda and Roy explain.

Introduction to SQL Server Spatial Data

More and more applications require the handling of geospatial data. It is easy to store spatial data, but it takes rather more thought to retrieve and manipulate it. Tasks like searching neighborhoods, and calculating distances between points is often required from databases. But how do you start? Roy and Surenda take you through the basics.

Which is the correct spatial data type?

Tuning Spatial Point Data Queries in SQL Server 2012

Spatial Point Data queries require particular tuning efforts to enhance performance and improve overall application through put. SQL Server 2012 introduces a few key new features and improvements to assist you in that goal.

Querying Geometry Information

Spatial Data Types

Vincenty Direct

Calculates the latlon coordinates for a given bearing and distance from reference latlon coordinates

Standardize data storage for geography spatial data type in SQL Server

Geography is one of the spatial data types introduced in SQL Server 2008. One of the characteristic of the geography data type is that it can accommodate any supported geometry based on any supported spatial reference system in the same field. So if the data that is stored in a column of geography data type is not standardized, it can be a very tedious and resource intensive task to figure out the geometry and spatial reference system associated with each value. To deal with this issue, we need to standardize the data stored in a field of that has the geography data type and in this tip we will look at how to deal with this issue.

Working with Spatial Data Part IV - Developing a Geospatial Dashboard (GIS)

In Part IV of the Geo-Spatial series, an interactive dashboard is developed to present and interact with the data.