Re: Oracle much slower than DB2?

In article <3B41EB18.2020202_at_tde-online.de>, Burkhard says...
>
>We have different projects with two environments:
>DB2 on AIX and Oracle on DEC UNIX. Now we wonder why a statement lasts
>on DB2 (17000 records) about 1 second, and on Oracle (11000 records
>only) more then 10 seconds. It's a simple update on several columns
>without condition. The machines should be comparable in CPU Speed.
>(compiling C code is faster on DEC UNIX). The AIX mschine has 256 MB of
>memory, the DEC machine 640 MB. The SGA on the DEC machine is 320 MB!
>The affected rows are off slightly different type: Smallint on DB2,
>Number (3) on Oracle.
>Any ideas, why performance is so bad in Oracle? (It's Oracle 8.0.5)

how big are your logs?

select group#, thread#, sequence#, bytes, members from v$log;

can you try it with sql_trace, timed_statistics, and tkprof and post the results?
http://asktom.oracle.com/~tkyte/tkprof.html

for a quick start on tkprof.

On my tiny little laptop (2 1meg logs), I get:

tkyte_at_TKYTE816> create table t as select object_id, object_name

     from all_objects where rownum < 11001;

Table created.

tkyte_at_TKYTE816> update t set object_id = -object_id; 11000 rows updated.

Elapsed: 00:00:00.11

tkyte_at_TKYTE816> update t set object_id = -object_id; 11000 rows updated.

Elapsed: 00:00:00.91

tkyte_at_TKYTE816> update t set object_id = +object_id; 11000 rows updated.

Elapsed: 00:00:00.91

tkyte_at_TKYTE816> update t set object_id = +object_id; 11000 rows updated.

Elapsed: 00:00:00.21

Under 1 second.

>--
>Burkhard Schultheis
>Tele Data Electronic
>Wagnerstr. 10
>D-76448 Durmersheim
>
>Email: schultheis_at_tde-online.de
>Phone: +49-7245-9287-21
>Fax: +49-7245-9287-30
>

--
Thomas Kyte (tkyte@us.oracle.com)             http://asktom.oracle.com/ 
Expert one on one Oracle, programming techniques and solutions for Oracle.
http://www.amazon.com/exec/obidos/ASIN/1861004826/  
Opinions are mine and do not necessarily reflect those of Oracle Corp