Enhancing the External Materialization

The intention of move "status" table to physical database is to increase durable and fully control refresh and loading, but it increase the complexity.
The "status" table by design should unique for whole VDB, if you look the https://teiid.gitbooks.io/documents/content/caching/External_Materialization.html#_usage_steps, the table structure:

CREATE TABLE status
(
  VDBName varchar(50) not null,
  VDBVersion integer not null,
  SchemaName varchar(50) not null,
  Name varchar(256) not null,
  TargetSchemaName varchar(50),
  TargetName varchar(256) not null,
  Valid boolean not null,
  LoadState varchar(25) not null,
  Cardinality long,
  Updated timestamp not null,
  LoadNumber long not null,
  PRIMARY KEY (VDBName, VDBVersion, SchemaName, Name)
);

but currently, one VDB may have multiple "status" table, each view may have it's own "status" table. Further more, we can consider create status table automatically, which like internal, status create once VDB start, and configured in VDB scope.

From finishedDeployment logic in MaterializationManager, MATERIALIZED_TABLE be used to determine whether the Mat is internal or external, But we lack the validation in metadata loading, in my previous test, the Internal Mat view configured lots of external view's properties like "status" table, the validation not throw excepton.