Hi Folks, Over at his blog , Nicklas Avéns questions the behavior of Filter. He's right: Filter is a little odd. It is also very much by design. Before we look at filter, let's review the data flow for a typical spatial query. A spatial selection generally...

Hi Folks, As part of a larger effort to document our protocols, SQL Server has just released documentation on the structure of our spatial types.  The document is also available in PDF .  Note that all of this is preliminary, and while I doubt...

Hi Folks, The title of this post states the obvious: the area of a sphere is finite.  We even have a nice formula for it, 4πr 2 .  The same is true for an ellipsoid, which is just a sat-upon sphere, although computing the area gets more complicated...

Hi Folks, Marko Tintor from our Serbia team just dropped some new functionality into the SQL Server Spatial Tools project on CodePlex: A method for testing whether a geography instance is valid. Better: a method for creating a valid geography from invalid...

Hi Folks, We all know that the sphere isn’t the plane, and that an ellipsoid is different as well, but I don’t know if everyone has given so much thought to the practical effects of these differences. And so I thought it might be a nice idea to catalog...

Hi Folks, This post contains no new information; it’s just a rollup of links to spatial indexing posts I’ve made.  If you want to know more about spatial indexing, these are the ones to read. In order: Why a Spatial Index? A Simple Spatial Indexing...

Simon Sabin asked me to pass along information about a free spatial event that he and Johannes Kebeck are holding in London on the 16th.  It looks like they’ll be covering a bunch of hot SQL Server Spatial topics: how to get your data in to SQL,...

Hi Folks, Jason Follas recently ran across a lingering issue when using our spatial library without the server.  I mistakenly thought the fix had been shipped, but for now it remains. The background is that the spatial library consists of a managed...

Hi Folks, It occurs to me that I haven’t posted anything about the hemisphere limitation for the SQL Server geography type.  This limitation is a little confusing, and could probably use some clarification. It also occurs to me that I haven’t posted...

Hi Folks, While I continue to procrastinate, here are some excellent spatial resources to peruse. First, David Lean, a Microsoft evangelist, has very comprehensive list of spatial posts over on his Dave does Data blog.  He covers a wide range of...

Last time , I posted a question sent to me by Rob Mount.  So what solutions exist other than the north pole? You did well: jnelso99 got part of the way there; tanoshimi finished it off.  We can find a set of circles around the south pole with...

Hi Folks, At PDC I gave a talk largely inspired by topics raised here and in the spatial forums.  But “inspired by” doesn’t equate to “a duplicate of”, and to turn things around, I’ve been meaning to write a few posts here inspired by my PDC talk...

This has come up a few times now.  Multiple questions deserve at least one answer, right? First, Microsoft has not produced a shapefile loader (or exporter).  If this is important to you, here’s the Connect item to hit.  (And yes: we do...

Despite my relative youth, I can be a bit of a fuddy-duddy. Fighting my natural impulses, I’ve decided to give Twitter a try---at least while I’m at PDC. So, if you’re interested in tracking me down, surf the tubes over to my very own Truman Show . Or...

Hi Folks, Spatial users often want to find the object nearest a given point. This operation, usually referred to as nearest neighbor search , is remarkably common in many areas of computer science. In general, we may wish to find not only the nearest...

Hi Folks, A post on the spatial forum last week caught my attention for entirely non-spatial reasons: it made use of two functions---RADIANS() and DEGREES()---that I never knew existed. It seems rather strange that out of the innumerable (well, technically...

Hi Folks, Unfortunately, I need to correct an earlier post of mine .  I will not be speaking at PASS this year---it looks like there were some mixed signals.  If you’re looking for your spatial fix, Michael Rys will be talking about types and...

Hi Folks, I'd like to let everyone know about a few conferences that I'll be at in the near future.  First up is PDC in Los Angeles at the end of October.  After that is the PASS Community Summit in beautiful Seattle middle of November. ...

Let's talk about projections---or at least about one very special projection: the gnomonic projection . Though it may not (or may?) be completely obvious, this post is related to the series of indexing posts that trailed off some months back, but it's...

I've seen a problem commonly phrased something like: I have X million records in a spatial table, and have created a spatial index, yet a simple select query takes me Y hours to complete. Ouch! If the problem is this extreme, the solution is usually pretty...

Hi Folks, This post is motivated by some recent discussion I've seen in the various tubes .  I don't mean to be critical of any of what's been said.  Rather I want to shine a little light on our thinking, processes, and tools.  We have...

Hi Folks, Marko Tintor, one of our spatial developers, just uploaded a bunch of new functionality to the SQL Spatial Tools project on CodePlex.  I've updated the list of contents on CodePlex, but Marko lays this out the addition quite simply himself...

Hi Folks, Let's kick this off with what may be a surprising result.  What should this code return? declare @g geometry = 'LINESTRING (0 0, 1 3)' declare @h geometry = 'LINESTRING (0 3, 2 0)' declare @i geometry = @g.STIntersection(@h).ToString()...

Hi Folks, I've just published a new project on CodePlex: SQL Server Spatial Tools .  The core idea is that instead of pushing up more samples showing how to extend our spatial functionality in text , we can put them in a more usable form.  Beyond...

Hi Folks, When we talk about lines on the Earth, we don't really mean straight lines: we following the surface of the Earth, and that is inherently curved.  Instead, when we talk about lines we mean great circles (or more precisely great elliptic...