Geometry Validity and Method Access
This article demonstrates how an invalid polygon (and linestring) are handled by the different database spatial APIs with correction in TSQL.
Spatial DB Types
Using Oracle’s ST_GEOMETRY type hierarchy with SDO_GEOMETRY: ST_PointN and ST_NumPoints
Oracle Spatial has, for many versions, made available an implementation of the OpenGIS SFS type hierarchy. Today I will show how to use this type hierarchy do extract points from an SDO_GEOMETRY. The first example extracts the first and last point from a linestring constructed from Well Known Text. The second example finds the firstRead More
Support for ESRI’s ST_GEOMETRY
The following article results from customers downloading the free source code (eg for Oracle SDO_GEOMETRY) on this site without fully understanding that the code is not for ESRI’s ST_GEOMETRY spatial type and then requesting changes to the source code to support that foreign type. So, to be clear, all of the source code, products andRead More
Spatial Database Training Courses
The following training courses have been developed and are available for on-site training using customer data: SQL Server Spatial Basic SQL Server Spatial Intermediate Oracle Locator and Spatial Oracle Location and Spatial Intermediate The courses can be delivered through GIS College or by contacting me directly. Courses for PostGIS and MySQL are being developed andRead More
Spatial Database Independence
I often hear asserted in discussions about accessing data in databases that the approach taken should be “database independent”. The assertion is always made as if it were some sort of Scientific Truth (Dogma even). And it is always assumed that this is easy to achieve. Finally, it always seems to be an accepted realityRead More
Spatial Database Comparison
I thought I would try and create a table comparing all the native spatial types of the main database products around today. Because this is a “work in progress”, I will be contantly updating it. Where I have something wrong or have missed a product, please email me and I will correct the table. ReginaRead More
Boarder and District Spatial Information Group Presentation on Spatial Datbases
On Tuesday November 11th 2008 I gave a 1 hour presentation on spatial databases entitled An Introduction to Spatial Databases to the Boader and District Spatial Information Group (BADSIG) at Albury NSW. The presentation was rather long as, generally, GIS practitioners are usually unfamiliar with database technology (no fault of their own) and so IRead More
SpatialWare 4.9 Released
I wrote this blog originally on the 18th of August when the announcement first hit my intray. I kept it hidden until I was happy with the factualness of the information it contains. Earlier this year MapInfo announced that the release of version 4.9 of SpatialWare for SQL Server (2005). (SQL Server 2000 is stillRead More