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.
Comparison
Identifying Quadrilateral Polygon Geometries in SQL Server Spatial
In some situations Quadrilateral polygon geometries in SQL Server Spatial can affect processing results. The best example of this is the identification of CircularStrings in polygon geometries. If quadrilateral objects are not identified, they end up being incorrectly converted. This function helps identify such polygon objects.
Using Range Querying to Filter LineString Segments
This article shows how to use range querying against cumulative length to filter/select LineString segments
How far inside, is inside? Measuring actual distance.
One issue that confuses a lot of spatial database practitioners is that the result of measuring the distance between a geometry object inside a polygon and that polygon’s boundary is zero (0). Here is an example. This looks like: Standard distance determination shows the problem: Here is a trick that will allow for the calculationRead More
Analyzing Spatial Query Performance Improvements in Oracle Spatial and Graph 12c Through Cross-Vendor Comparison
I have written an analysis of Oracle 12c’s new spatial performance improvements. The analysis was conducted by comparing what Oracle is offering in Oracle Spatial 12c against two other database types that have a reputation for performance and functionality. The report is available at the following link Accessing the Improvements These spatial performance improvements areRead More
Update Triggers and SDO_GEOMETRY Equality
It is not uncommon to want to construct BEFORE INSERT row level triggers that detect and process changes to SDO_GEOMETRY columns and assign other column values. However, the rules that govern the comparison of objects such as numbers, dates, strings etc do not apply to complex objects such as SDO_GEOMETRY. As such, to correctly detectRead More