Re: Convert SAP Oracle Database to IBM DB2 Database??
From: DA Morgan <damorgan_at_psoug.org>
Date: Thu, 07 Feb 2008 21:58:39 -0800
Message-ID: <1202450291.996022@bubbleator.drizzle.com>
>> Serge Rielau wrote:
>> I would but there is a rather substantial problem: Chris Eaton's
>> understanding of Oracle compression appears to not even include
>> the marketing materials much less the rather substantial discussion
>> of the concepts and architecture.
>> What I'm saying is that it is not just superficial ... from a
>> technical point-of-view it is mostly incorrect. He needs to learn how
>> to read the
>> on-line docs.
END LOOP;
COMMIT;
END;
/
Date: Thu, 07 Feb 2008 21:58:39 -0800
Message-ID: <1202450291.996022@bubbleator.drizzle.com>
Serge Rielau wrote:
> DA Morgan wrote:
>> Serge Rielau wrote:
>>> DA Morgan wrote: >>>> Serge Rielau wrote: >>>>> DA Morgan wrote: >>>>>> Serge Rielau wrote: >>>>>>> DA Morgan wrote: >>>>>>>> My testing of Oracle compression versus DB2 compression >>>>>>>> indicates that >>>>>>>> DB2 has some catching up to do. >>>>>>> Interesting, care to elaborate? Always thriving to improve... >>>>>>> Given Oracle's DeWitt clause I'll gladly accept any information >>>>>>> you have by email as to not get you into trouble. >>>>>> Going to have to disappoint you this time for reasons I am sure >>>>>> you can >>>>>> appreciate. >>>>> So an unsubstantiated claim... Aside you should use DB2 9.5 to >>>>> compare to Oracle 11 >>>> >>>> If I'd used Oracle 11 I would have. >>>> >>>> But as long as you are actively participating how about a brief >>>> technical presentation from the expert explaining to us how compression >>>> in DB2 differs from that in Oracle 10g and 11g. >>>> >>>> Please include also information as to how headers are designed and how >>>> blocks are filled? Top down as in Informix for both Top-Down and >>>> Bottom-Up as in Oracle? Or some other means. >>> http://blogs.ittoolbox.com/database/technology/archives/compression-in-11g-vs-db2-9-21173 >>> >>> Maybe we can also take the discussion there.... >>> >>> Cheers >>> Serge >>
>> I would but there is a rather substantial problem: Chris Eaton's
>> understanding of Oracle compression appears to not even include
>> the marketing materials much less the rather substantial discussion
>> of the concepts and architecture.
>>
>> What I'm saying is that it is not just superficial ... from a
>> technical point-of-view it is mostly incorrect. He needs to learn how
>> to read the
>> on-line docs.
> Well the nice thing about BLOGs is the ability to give feedback. > You are a teacher, no? Teach! > > Cheers > Serge
Teach someone from IBM? I wouldn't presume to do such a thing.
But here's something for those might want to consider the value of that blog entry.
CREATE TABLE t1 (
testcol VARCHAR2(50))
TABLESPACE uwdata;
CREATE TABLE t2 (
testcol VARCHAR2(50))
TABLESPACE uwdata COMPRESS;
DECLARE
x t1.testcol%TYPE;
BEGIN
FOR i IN 1 .. 100000 LOOP
SELECT dbms_crypto.randombytes(25) INTO x FROM dual; INSERT INTO t1 VALUES (x); INSERT INTO t2 VALUES (x);
END LOOP;
COMMIT;
END;
/
- some sample rows: 3605CAA721159CAC4E462B841419CCB7390F1AE3484FF14963 05B7AE0B6BB076EEAF3E8E7DBA1BE9D5C8F97737AA1FDF21A5 40756BCEBF00CCB80ACA5F4F6BF3AFE6BC19D19EA74F10212B 234812A15930421A208BCF19C943762B5FA11D0C0C7E811F5E 4177AFC94C248D6B6765B8CE45FE3E49E2E5456BA6BA48C147
SELECT table_name, blocks
FROM user_tables
WHERE table_name IN ('T1', 'T2');
TABLE_NAME BLOCKS ------------------------------ ---------- T1 780 T2 701
Hmmmmm.
-- Daniel A. Morgan Oracle Ace Director & Instructor University of Washington damorgan_at_x.washington.edu (replace x with u to respond) Puget Sound Oracle Users Group www.psoug.orgReceived on Thu Feb 07 2008 - 23:58:39 CST