External Data Sources: connection is dead

So far I’m able to connect to PostgreSQL as external data source and create RDF Views on top of this connection.
By the way I get sometimes an error message: “… connection is dead”. Do you have any idea on why this happens?
thanks

This is the error message:

SQL State S1000
SQL Message VD052: Remote DSN PostgreSQLU: [OpenLink][ODBC][PostgreSQL Server]connection is dead in _sql_tables:(BIF), DB.DBA.sql_tables, vc_after_data_bind_catalog_list, vc_data_bind, __udt_method_call:(BIF), vc_data_bind, __udt_method_call:(BIF), vc_data_bind, __udt_method_call:(BIF), vc_data_bind, __udt_method_call:(BIF), vc_data_bind, __udt_method_call:(BIF)

The connection is dead error message generally occurs when the backend PostgreSQL database is not responding to requests even after an attempt to reconnect. Please create and provide an ODBC trace of such an occurrence of this error so we can see at which point it is occurring. The PostgreSQL logs should also be checked to see if there might any messages there indicating the server might have had problems or on the network itself.

Thanks for the answer. Will check with our DB esperts