ORA-04091: table name is mutating

Question

I get ORA-04091 Error while inserting data into table A. Table A records are refferencing other records in the same table 1:N. Father records have fk_id = null and child record

Answer 1

You know what the problem is, so just read your code a little: you update the same table you are putting the trigger on.

I guess in your case you just need to put :NEW.actualTS:=current_timestamp, without using the update statement.