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SQL Server 2008 Spatial data - geography & geometry, all in one

Geography & Geometry has much significance in day to day life, within that as a data now you can manage within your Database using SQL Server 2008 new data type - spatial, this represents information about the physical location and shape of geometric objects. More from here - SQLServer-spatial-demos

Posted to SQL Server Knowledge Sharing Network (SqlServer-qa.net) (Weblog) by ssqa.net on 03-20-2008
Spatial data where to download

I'm going to build a list of locations to download spatial data for free. This is the first http://arcdata.esri.com/data_downloader/DataDownloader?s=s&service=ESRI_World It allows you to downloads country boundaries, roads, water bodies and cities if ((typeof(socialButtons))!="undefined") { socialButtons...

Posted to SimonS Blog on SQL Server Stuff (Weblog) by simonsabin on 02-07-2008
SQL Server 2008 Spatial - STContains for Geography type

Where is the STContains function for the Geography type. I don't know but its not in Sql Server 2008. As a workaround you can use STIntersection and compare the results with the geography you are comparing with i..e declare @g geography = 'POLYGON((0 0,0 10,0 20,0 30, 0 40, 50 40,50 30 ,50 20, 50 10...

Posted to SimonS Blog on SQL Server Stuff (Weblog) by simonsabin on 01-21-2008
Viewing Geometries on Virtual Earth

One of the biggest challenges in understanding spatial data is visualising shapes. In 2D it isn't two bad, and I have started the SpatialViewer project on codeplex ( http://www.codeplex.com/SpatialViewer ) However visualising Geography types requires a globe.Virtual Earth can come to the rescue. I have...

Posted to SimonS Blog on SQL Server Stuff (Weblog) by simonsabin on 01-15-2008
SQL Server 2008 Spatial - How to create a circle?

How do you create a circle in a planar system. Ok so there are some funky algorithms for creating a set of points all the way round the circle. Well there is a much easier way. Create a point i.e. POINT (10 10) and the use the STBuffer(radius) method to get a circle whose centre is at the point and with...

Posted to SimonS Blog on SQL Server Stuff (Weblog) by simonsabin on 01-09-2008
SQL Server 2008 Spatial - Performance of database calls follow up

I recently blogged about the performance of passing spatial data to the database.( SQL Server 2008 Spatial - Performance of database calls? ) In it I found that the the performance radically dropped off as the number of points increases. Whilst this was suprising I had used my usual approach of eliminaing...

Posted to SimonS Blog on SQL Server Stuff (Weblog) by simonsabin on 01-08-2008
Spatial Perf

Posted to Blog Images (Gallery) by simonsabin on 01-07-2008
SQL Server 2008 Spatial - Performance of database calls?

There are 4 ways of holding spatial data, Well Known Text (WKT), Well Known Binary (WKB), Geography Markup Language and the base spatial type (SqlGeometry or SqlGeometry). This leads me on to the question how should you pass the data to SQL Server. I've heard bad things about passing udts and so expected...

Posted to SimonS Blog on SQL Server Stuff (Weblog) by simonsabin on 01-07-2008
SQL Server 2008 Spatial - Which is faster WKT or WKB?

I've just posted two methods for creating geometries in client code. The examples use Stylus points from an ink canvas but any collection of points will go. After doing that I ran some tests to compare the two. I found that in generally the WKB method was ~70% faster to build the WKB and 40% faster to...

Posted to SimonS Blog on SQL Server Stuff (Weblog) by simonsabin on 01-04-2008
SQL Server 2008 Spatial - Converting from Ink Strokes to geometries

The following snippet will convert an strok collected using an Ink Canvas in WPF to a LINSTRING geometry. The first uses the Well Known Text format WKT. //Text representation of a line is LINESTRING (x1 y1,x2 y2 x3 y3....) //create an string array to store the points string [] pnts = new string [e.Stroke...

Posted to SimonS Blog on SQL Server Stuff (Weblog) by simonsabin on 01-04-2008

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