Fixing Geography Ring Orientation
This article demonstrates the effect wrong ring orientation has on the processing of a geography object and shows how to fix such orientation.
Some article are about algorithms, some about implementations, some about low level functions. This is the latter.
This article demonstrates the effect wrong ring orientation has on the processing of a geography object and shows how to fix such orientation.
This article shows how to remove duplicate vertices/point in SQL Server Spatial geometry objects.
This article shows how to construct a function that allows any linestring to be split by any point using a collection of SDO_LRS procedures and functions.
This article describes how to split a linestring or a multilinestring using PL/SQL at a known point.
Installing GeoRaptor for SQL Developer 18+ GeoRaptor is available as a full installable download from this site. Otherwise it can also be compiled from the public source which is available from github. To download GeoRaptor first go to the online shop and click on the GeoRaptor product. Note that there is no charge ($0) forRead More
Introduction A lot has been written, positive and negative, about the speed of Oracle Spatial over the years, a lot of ill informed (I mean if you don’t use it, how can you criticize it?). But since Oracle Database 12c (12.1) there is no longer any doubt as to the speed of the product. Why?Read More
This articles logically steps through all the functions in a complete package of Linear Referencing functions that I have written for TSQL. The article both demonstrates the power of SQL Server Spatial but what can be done with TSQL.
Sometimes it is a data quality requirement for linear data (roads, pipelines, transmission lines) that curves within the lines must have a radius greater than a particular amount. Recently a customer asked me to write some TSQL functions to help them run data quality checks over linear data loaded into a SQL Server 2008 geometryRead More
Introduction The OGC operators for geometry processing only support two polygon inputs. Additionally the Microsoft aggregate operators only include geometry union processing geometry::UnionAggregate and not overlay processing etc. UnionAggregate returns for all input polygons as the single Union (see above) does. Concept: Resolving all overlapping areas, without dissolving boundaries, is called “planar enforcing”. Planar enforcementRead More
Introduction Warning: This article is long mainly because it includes the source code of the Hilbert, Morton and Peano key/curves. I would assert that space filling curves have always been overlooked in their use within GIS. Their existence was/is rarely taught at Universities, though at least in my day. Perhaps today it is different (butRead More