When trying to execute any query via the SQL Commander of DbVisualizer 14.0, and using Datacom Server (DBSRV) TYPE 4 connection, the following pop-up is displayed:
Release : 15.0
The "The database connection has been lost" error can be resolved using the workaround outlined on the DbVisualizer knowledge Article "Any statement I execute in the SQL Commander results in "Database connection is not open"".
It is advised to set the validation query to the string 'disabled', so that performance is not affected. Although, there is a clause stating "things may not always work right if a connection is dropped by the server", it does not apply to Datacom Server.