Execution of metadata query may lead to internal server error

In rare scenarios there can be an exception during execution of a metadata query (e.g. in ODBC SQLPrimaryKeys() or in JDBC getColumns()) which will cause an internal server error.
The client will receive following message instead of the expected exception text:

Successfully reconnected after internal server error, transaction was rolled back.

In most cases the command will be successful, if it is executed again.