How to speed up SQL spatial query (spatial index error)

Question

Hi,
Im trying to split polylines by points which have a small buffer around them. Currently i have over 370,000 lines and 320,000 nodes and the query is running really slowly (ive left it for 3 days and it still hasnt completed). I have tried forcing a spatial
index using with (Index(SI_tempPD)) but i get the following error:
"The query processor could not produce a query plan for a query with a spatial index hint. Reason: Could not find required binary spatial method in a condition. Try removing the index hints or removing SET FORCEPLAN."
below is the snippet of code that im trying to run when i get the error:
BEGIN INSERT INTO TempLines ( [linenum] ,[ogr_geometry] ) SELECT lines.[linenum] ,lines.[ogr_geometry].STDifference(points.[ogr_geometry].STBuffer(0.005)) AS ogr_geometry FROM dbo.TemplineData AS lines with(Index(SI_tempPD)) INNER JOIN dbo.[TemplineNodes] AS points ON lines.[ogr_geometry].STIntersection(points.[ogr_geometry]).STDistance(points.[ogr_geometry]) < 1 WHERE (lines.[linenum] <> points.[linenum]) END
 is there anyway i can speed up the query? (I also have a clustered primary key) the execution plan shows that a filter takes up 36% of the cost and the insert takes up 64%
Any help would be greatly appreciated! (im using SQL Server 2008 (SQL server Management studio 10.50.1600.1))

Answer 1

SQL Server spatial indexes don't support STDifference or STIntersection, see
https://technet.microsoft.com/en-us/library/bb895373(v=SQL.105).aspx, which is why you get the error. 
Your query is doing multiple expensive spatial operations against some fairly good-size tables in a join. You might get better results by either breaking the query into multiple simpler queries (SELECT into a temporary table and move the STDifference and
STBuffer and INSERT off to a separate statement), and (if possible) rearchitecting the query to use STIntersects (which does support spatial index) rather than STIntersection.
Hope this helps, Bob