Spatial Solutions Architect and Database Expert
My EXPORTER package + Java code has a function called WriteDelimitedTextfile that can be used to export any SQL SELECT statement to disk using Oracle database’s DBMS_JOB or DBMS_SCHEDULER. Yes, you can export to disk via pure PL/SQL but I have added this function to my EXPORTER to create an integrated solution for exports thatRead More
This is an old article that uses older custom code e.g. Vector2Geom(). Because the principles in the code are correct, I will bring the code up to date if anyone shows any interest. When investigating geometric or topological errors for linear or polygonal geometry objects, a range of tools are needed. Oracle has basic toolsRead More
Recently, using SQL Server 2008 (not R2), I came across an issue with hinting a SELECT statement with a spatial index. This particular issue is different from the one Bob Beauchem wrote about in his article On hinting spatial indexes and query complexity (in turn he references Isaac Kunen’s Is my spatial index being used?).Read More
I have had the need, over the years, to produce statistics that helped me decide how effective a change to a property of a spatial table or index might be. For example, with SQL Server 2008’s Spatial Index, for most sites, setting the right properties to get the best performance is a trial and errorRead More
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
Java classes loaded into the Oracle JVM are interpreted when executed up to and including Oracle 10gR2. For Oracle 11g and upwards, these loaded Java classes can be compiled to native code. I have added the optional compilation of my JTS Java wrappers and the source JTS classes to the JTS installer. The installation isRead More
I have had the need, over the years, to produce statistics that helped me decide how effective a change to a property of a spatial table or index might be. Back in the old days of the Quad Tree index, I used a procedure like the following, to work out the best properties for aRead More
In my exploration of the possibilities of using Java Topology Suite’s (JTS) robust algorithms with Oracle SDO_GEOMETRY I have moved to expose three methods within JTS’s GeometrySnapper (com.vividsolutions.jts.operation.overlay.snap) class: snap – Snaps two geometries to each other with both being able to move. snapTo – Snaps the vertices of the source geometry to the verticesRead More
Today I decided to expose the Java Topology Suite’s (JTS) MinimumBoundingCircle functionality via the Spatial Companion For Oracle (SC4O) installer and package. The MinimumBoundingCircle PL/SQL wrappers I have created are: Here are some examples. Now let’s test and visualise some lines and circles. Which look like: 1. Line !http://www.spatialdbadvisor.com/images/134.png! 2. Rectangle !http://www.spatialdbadvisor.com/images/135.png! I hope thisRead More
I created a densify function within my GEOM package in pure PL/SQL many years ago. Today I decided to expose the Java Topology Suite’s (JTS) Densifier functionality via the Spatial Companion For oracle (SC4O) installer and package. The Densify PL/SQL wrappers I have created are: Here is an example using a 3 point line. WhichRead More