Unable to delete an PostgreSQL materialized view from ArcMap, ArcCatalog or ArcGIS Pro.

Solução Provisória

For materialized views registered with geodatabase:

1. From pgAdmin, drop the materialized view.
2. Right-click and delete the view as the view is still in the Catalog tree.

For materialized views not registered with geodatabase:   

1. From pgAdmin, drop the materialized view.

Etapas para Reproduzir