How to use CLOB

Question

When I use CLOB like
CREATE OR REPLACE PROCEDURE Example_1b(retData out clob) IS
src_lob cLOB;
BEGIN
SELECT b_lob INTO src_lob
FROM lob_table
DBMS_LOB.APPEND(dest_lob, src_lob);
COMMIT;
EXCEPTION
WHEN some_exception
THEN handle_exception;
END;
There are thousand records in lob_table.When I run the procedure,It's very very slowwer !
How to improve it?

Answer 1

I assume there are some lines missing here.
>
1 CREATE OR REPLACE PROCEDURE Example_1b(retData out clob) IS
2 src_lob cLOB;
3 BEGIN
4 SELECT b_lob INTO src_lob
5 FROM lob_table
6 DBMS_LOB.APPEND(dest_lob, src_lob);
7 COMMIT;
8 EXCEPTION
9 WHEN some_exception
10 THEN handle_exception;
11 END;
[unquote]
Is there a where clause missing after line 5 or is it your intent to select your whole clob table? If it is, then you should use a curser like so:
>
1 CREATE OR REPLACE PROCEDURE Example_1b(retData out clob) IS
2 CURSOR c1 is SELECT b_lob
3 FROM lob_table;
4
5 src_lob cLOB;
6 BEGIN
7 for src_lob in c1 loop
6 DBMS_LOB.APPEND(dest_lob, src_lob);
7 end loop;
8 EXCEPTION
9 WHEN some_exception
10 THEN handle_exception;
11 END;
[unquote]
Please note, I removed the commit at line 7 as it was unecessary in your procedure (you showed no inserts, updates, or deletes).