I feel close but couldn't happen to pass this step:
I've created a java adapter based on PorftolioDemo adapter example which polls a database and returns the records. Initially, it returns these records (which the client isn't aware of these items' names) successfully with "ADD" command to the table created as such below:
var newTable = new DynaMetapushTable("spot", schema, "COMMAND");
newTable.onChangingValues = updateItem;
newTable.setMetapushFields(2, 1);
newTable.setMetapushSort(5, true);

"UPDATE" and "DELETE" commands also run on this metapushtable.
However, I couldn't succeed one thing: if a new record is inserted to the database i try to push this record to the client with the "ADD" command using listener.update. And the client doesn't receive anything with the below warning coming from the adapter:
< WARN> Unexpected update for item spot39

Any advices are welcome and thanks in advance,