[postgis-devel] 3D Index / 2D Index concerns

[Paragon Corporation]

Slight amendment,

> Given everything people have said, would seem ideal to make this decision
at runtime rather than at index build.

But if speeds can not be made the same e.g. a 2D index since it use fixed
length is always faster than a 3D index and you never care about 3D checks
even on a 3D geometry, then 
I guess it would be better to explicitly specify it.  Though even that seems
like a bit of a short-sighted solution.

I would still go with basing the index on the geometry dimension for the
share fact that if you don't care about a Z component and you are lugging
around a Z component you are just wasting unnecessary disk space.
It adds a bit to the troubleshooting, but in the end you really should know
if your geometries have a Z or not.

So what was I saying -- just thinking out loud

Thanks and sorry to be a nag,
Regina