we're using FDO Postgis provider in Mapguide open source.
In particular FDO 3.8.
It seems that materialized views are not (yet) supported.
We can workaround the problem creating a regular view that selects all data from the materialized views but then FDO is unable to find a primary key and in general to retrieve information about constraints.
Unfortunately AFAIK materialized views are not exposed through information_schema since they are not exactly part of SQL standard.
They may be found selecting data from pg_class where relkind='m'.
This obviously is postgresql specific.
Is there any plan to support materialized views in PostGIS FDO?