ORA-22828 输入样式或替换参数超过了32k大小限制

今天调试程序报以下错误：

ORA-22828: input pattern or replacement parameters exceed 32K size limit
22828. 00000 -  "input pattern or replacement parameters exceed 32K size limit"
*Cause:    Value provided for the pattern or replacement string in the form of
           VARCHAR2 or CLOB for LOB SQL functions exceeded the 32K size limit.
*Action:   Use a shorter pattern or process a long pattern string in multiple
           passes.

可用以下脚本重现：

declare
  cb clob;
  ret_cb CLOB;
begin
  cb := rpad('x', 32767, 'x')||'x';
  ret_cb := '<resp>#result#</resp>';
  ret_cb := replace(ret_cb, '#result#', cb);
end;
/

解决方式如下：

编写函数：

create or replace function replace_with_clob
  (i_source in clob
  ,i_search in varchar2
  ,i_replace in clob
  ) return clob is
  l_pos pls_integer;
begin
  l_pos := instr(i_source, i_search);
  if l_pos > 0 then
    return substr(i_source, 1, l_pos-1)
        || i_replace
        || substr(i_source, l_pos+length(i_search));
  end if;
  return i_source;
end replace_with_clob;

改写后：

declare
  cb clob;
  ret_cb CLOB;
begin
  cb := rpad('x', 32767, 'x')||'x';
  ret_cb := '<resp>#result#</resp>';
  ret_cb := replace_with_clob(ret_cb, '#result#', cb);
  dbms_output.put_line(substr(ret_cb, 1, 100));
end;
/

执行成功！

-----------------------------------

Dylan    Presents.