* test get_table_names
* test _get_full_name
* add test_split_data_type
* test _show_columns
* add test_is_column_name_quoted
* test select_star
* test get_view_names
* test estimate_statement_cost
* test get_all_datasource_names
* test get_create_view
* test _extract_error_message
* fix typo