PostGIS and spatial database

So, does postGIS have it's own sql engine, or does it utilize the postgres sql. Can the two datatypes, the geometric and geographic be extended in the same fashion that a java class can be subclassed?

Thank-you

Connie Irwin

Hi Connie,

Already replied to your other post, but just in case it helps:

* PostGIS builds upon the existing geometric data types in PostgreSQL.
* PostGIS also extends the existing indexing mechanisms in PostgreSQL to support indexing of spatial data, which obeys different rules from scalar data.
* PostGIS provides a set of additional spatial functions that can be used within SQL (and PGPLSQL) code, but the underlying SQL engine is provided by PostgreSQL itself.

Hope this helps a bit.

(And where are the PostGIs authors anyway?)

Chris