问UTL_FILE.FGETATTR返回块大小为0

EN

DECLARE
    v_fexists       BOOLEAN;
    v_file_length   NUMBER;
    v_block_size    BINARY_INTEGER;
BEGIN
    UTL_FILE.FGETATTR ('TEST_DIR','temp file.txt',v_fexists,v_file_length,v_block_size);
    IF v_fexists THEN
        DBMS_OUTPUT.PUT_LINE('The file exists');
        DBMS_OUTPUT.PUT_LINE('Its length is     :'||v_file_length);
        DBMS_OUTPUT.PUT_LINE('Its block size is :'||v_block_size);
    ELSE
        DBMS_OUTPUT.PUT_LINE('The file does not exist!');
    END IF;
END;

PL/SQL procedure successfully completed.

The file exists
Its length is     :2794
Its block size is :0