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April 2012

The PIM Constraint, Improving Geospatial Database Integrity
Friday, April 27, 2012

The PIM now contains sets of features (the pimFeature) grouped into sets (the pimConfiguration) with properties and referencing sets of attributes (the pimAttribute).  For may GIS solutions, this is all that is required for collecting, validating, and displaying geospatial data. 

But the PIM also contains the ability to constrain attribute values in a variety of ways, in much the same way that many of the RDBMS data stores contain a similar ability.  Probably the simplest of these ways is the 'Nulls Allowed' property.  In nearly all cases, attributes will be coded as 'Nulls Allowed', but specific user preferences might dictate otherwise, provided the user fully understands the implications of this coding. 

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Introduction to PIM Attributes
Monday, April 16, 2012

A quick review of the pimConfiguration to the pimFeature shows...

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The PIM Feature, Introduction and Application in GIS
Friday, April 6, 2012

In a previous post, we discussed the meaning of the pimConfiguration as a collection of elements in the Platform Independent Model (PIM).  One of those elements (in fact, the most important geospatial one) is the pimFeature.  The pimFeature is that table/object that defines the geometric object that gets displayed on the map, sometimes called the 'shape'.  It is defined based on the contents of the pimGeometry table within the PIM.  These are currently defined as Point, Line/Polyline, or Polygon but could be easily expanded to 3D geometries and multipart geometries.

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