--에러 발생
SELECT SUBSTRB(clob_column, 1, 10) FROM table_name;
--ORA-22998: CLOB or NCLOB in multibyte character set not supported
--아래의 쿼리로 실행
SELECT SUBSTR(clob_column, 10, 1) FROM table_name;
SELECT DBMS_LOB.SUBSTR(clob_column, 10, 1) FROM table_name;