Current SQL Server Blog Articles
• Function to Scale a geometry object for SQL Server Spatial
• TSQL String Tokenizer Function for SQL Server
• geography/geometry to MBR helper functions
• generate_series for SQL Server 2008
• Extract Polygons from result of STIntersection in SQL Server Spatial
• Function to round ordinates of a SQL Server Spatial geometry object
• Extract elements of SQL Server Spatial geometry object
• Counting number of polygon rings SQL Server Spatial
• Filtering Polygon Rings in SQL Server Spatial
• Function to Move a geometry object in SQL Server Spatial
• Alternate Centroid Functions for SQL Server Spatial
• Function to Rotate geometry objects in SQL Server Spatial
• A GetVertices wrapper for DumpPoints in SQL Server 2008 Spatial
• Creating a Morton number Space Key generator for SQL Server
• Gridding a geometry or geography object (SQL Server Denali)
• On hinting spatial indexes
• Random Search Procedure (SQL Server 2008 Spatial)
• COGO: Converting (Google Earth) Formatted Longitude/Latitude points to decimal degrees (SQL Server)
• COGO: Convert Degrees, Minutes and Seconds values to Decimal Degrees
• COGO: DD2DMS Formatting a latitude/longitude decimal degree value
• COGO: Create point from bearing and distance
• COGO: Compute number of vertices required to stroke circle or circular arc
• COGO: Calculating the bearing between two points (SQL Server 2008 Spatial)
• COGO: Compute arc length subtended by angle centre of circle
• COGO: Compute chord length of segment of a circle (arc)
• COGO: Computing Arc To Chord (Arc2Chord) Separation
• COGO: Creating a stroked polygon from a circle's centre x,y and radius
• COGO: Finding centre and radius of a curve defined by three points: FindCircle function
• Identifying Tight Radius Curves sections within LineString geometry data
• Generating random point data for SQL Server 2008 Spatial
• New Presentation on Active (Searchable) Spatial Metadata for SQL Server 2008 Spatial and FreeText
• Checking is a column in a table or a view is of type geometry or geography
• Extracting geometry type string values from geometry/geography objects in SQL Server 2008 Spatial
• Vectorising geometry objects in SQL Server 2008
• MBR to geography/geometry helper functions
• Extracting geometry types from geometry/geography objects in SQL Server 2008
• Getting the number of coordinate dimensions of a geometry/geography object in SQL Server 2008
• A Dump Points Function for SQL Server 2008 Spatial
• toGeography and toGeography Conversion Functions for SQL Server 2008 Spatial
• Write text file with spatial data from SQL Server 2008
• Loading Shapefiles into Geography type column in SQL Server 2008
• Tip #6: Correcting invalid geometries
• Tip #5: Where or where has my little column gone
• Tip #4: What Coordinate System is that?
• Tip #3: What object is that?
• Tip #2: Spatial Indexing and Primary Keys
• Tip #1: SQL Server 2008 "Katmai" - Setting SRIDs
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?).
The difference with the issue I found is to do with a very simple query that uses a constructed geometry. Here is the original coding of the query:
Now, there could not be anything more simple that this query, so why is an error being thrown?
Following a hunch I discovered (I think) that the geometry::STLineFromText() constructor is the culprit. On this basis, I played around with the query and, using a CTE, came up with the following that correctly uses the spatial index.
Note: The reason for the “(SELECT TOP 1…. )” in the CTE is because I want the constructed linestring to have the same SRID as the host table.
Here is that part of the actual explanation plan showing the use of the spatial index.
Perhaps this is no longer an issue in R2 or Denali.