We’re intending to move to Oracle 11gr2. After installing, I performed a import of some data and found some wait events, such as “kfk: async disk IO”.

Searching the web, I found this page. I am also trying to get more information at Oracle’s support – it’s a dificult task!

I could not get access to the SR you’ve opened. Could you, please, let me know what was told there?

Regards,

Flávio.

I also mixed 11gR2 ASM with 10g R2 database and speeds were fine

Rgds
Abhay.

The SR was 7013191.994 (10046 LEVEL 8 TRACE EMITS “PARSING IN CURSOR #” RECORDS FOR EVERY SQL EXECUTION) and it references bug number 7309111. The client was happy with the downgrade solution so I didn’t pursue the SR much after that. I’d love to hear if you get any further with the issue.

Best Regards,
Dave

Here is my script that I have been using:
alter session disable parallel query;
set termout on;
prompt ** Nested loop speed test
set timing on;
prompt ———————–
prompt ** Drop table if it exists
drop table a;
prompt ———————–
prompt ** Create table
create table a
(id1 number not null,
id2 number not null,
id3 number not null)
;

prompt ———————–
prompt ** Put data in the table
begin
for i in 1..10000000 loop
insert into a(id1, id2, id3)
values (i, i, i);
end loop;
commit;
end;
/
prompt ———————–
prompt ** Create an index
create unique index a on a(id1, id3);

prompt ———————–
prompt ** Put statistics on the table and index
begin
dbms_stats.gather_table_stats(
user,
‘a’,
cascade=>true,
estimate_percent=>100,
method_opt=>’FOR ALL COLUMNS SIZE 254′,
no_invalidate=> false);
end;
/

prompt ———————–
prompt ** Run the test query three times
prompt ** First run
select /*+ use_nl(A B) */count(a.id3)
from a a, a b
where a.id1=b.id2;
prompt ———————–
prompt ** Second run
select /*+ use_nl(A B) */count(a.id3)
from a a, a b
where a.id1=b.id2;
prompt ———————–
prompt ** Third run
select /*+ use_nl(A B) */count(a.id3)
from a a, a b
where a.id1=b.id2;
prompt ———————–
prompt ** Delete from plan table
delete from plan_table where statement_id = ‘Nested Loop Speed Test’;
prompt ———————–
prompt ** explain plan
explain plan set statement_id = ‘Nested Loop Speed Test’ for
select /*+ use_nl(A B) */count(a.id3)
from a a, a b
where a.id1=b.id2;
prompt ———————–
prompt ** Query plan table
select operation
from plan_table p
where p.statement_id = ‘Nested Loop Speed Test’
and p.operation in (‘NESTED LOOPS’, ‘HASH JOIN’);
prompt ———————–
prompt ** Delete data from the table
delete from a;
commit;
prompt ———————–
prompt ** Put data in the table with index
begin
for i in 1..10000000 loop
insert into a(id1, id2, id3)
values (i, i, i);
end loop;
commit;
end;
/
prompt ———————–
prompt ** Update table
update a set id1 = id1;
commit;