问题
Recently, I need to do some performance test against oracle 10g, the case is that I need to prepare as many records as possible which has blob columns, and the blob column must at least contain 10kbs of data.
How do I automatically generate the test data? Say, 10,000 records?
回答1:
If you do not care that the content of the LOB data is the same, you can use the following (creating one random 10000 bytes lob value):
declare
v_clob clob;
v_blob blob;
v_dest_offset integer := 1;
v_src_offset integer := 1;
v_warn integer;
v_ctx integer := dbms_lob.default_lang_ctx;
begin
for idx in 1..5
loop
v_clob := v_clob || dbms_random.string('x', 2000);
end loop;
dbms_lob.createtemporary( v_blob, false );
dbms_lob.converttoblob(v_blob,
v_clob,
dbms_lob.lobmaxsize,
v_dest_offset,
v_src_offset,
dbms_lob.default_csid,
v_ctx,
v_warn);
insert into blob_test (id, data)
select rownum, v_blob from dual
connect by level <= 10000;
end;
/
See here an example session:
SQL> create table blob_test (id number primary key, data blob);
Table created.
SQL> declare
2 v_clob clob;
3 v_blob blob;
4 v_dest_offset integer := 1;
5 v_src_offset integer := 1;
6 v_warn integer;
7 v_ctx integer := dbms_lob.default_lang_ctx;
8 begin
9 for idx in 1..5
10 loop
11 v_clob := v_clob || dbms_random.string('x', 2000);
12 end loop;
13 dbms_lob.createtemporary( v_blob, false );
14 dbms_lob.converttoblob(v_blob,
15 v_clob,
16 dbms_lob.lobmaxsize,
17 v_dest_offset,
18 v_src_offset,
19 dbms_lob.default_csid,
20 v_ctx,
21 v_warn);
22
23 insert into blob_test (id, data)
24 select rownum, v_blob
25 from dual
26 connect by level <= 10000;
27
28 end;
29 /
PL/SQL procedure successfully completed.
SQL> select count(*) , max(length(data)) from blob_test;
COUNT(*) MAX(LENGTH(DATA))
---------- -----------------
10000 10000
If you want to have different data you can generate and insert v_lob in a loop instead.
来源：https://stackoverflow.com/questions/14556313/prepare-test-data-on-oracle-with-blob-column