PostGIS is a product from Refractions Research that adds support for a PostGIS spatial data type to PostgreSQL databases. PostGIS follows the Open Geospatial Consortium, Inc. (OGC), Simple Features specification for SQL. It uses the OGC well-known binary (WKB) and well-known text (WKT) representations of geometry. Essentially, PostGIS adds a spatial type to PostgreSQL.
Feature classes of the PostGIS type have a business table containing a spatial column of type geometry.
Once a geometry column is added to a table, it must be registered with ArcSDE using the sdelayer –o register command if you want to use the data with an ArcSDE client application. Consult the ArcSDE Administration Command Reference for details on using this command. Or, PostGIS tables can be read directly into ArcGIS if you are using the ArcGIS Data Interoperability extension.
Consult the PostGIS documentation for information on structured query language (SQL) syntax used to create spatial columns using PostGIS, verify the geometry, and access tables and spatial columns of type geometry.
