Antwort: [DB2-L] SV: [DB2-L] Antwort: [DB2-L] partitioning in V8

Roy Boxwell

Antwort: [DB2-L] SV: [DB2-L] Antwort: [DB2-L] partitioning in V8
Hi

Only true if you copy all parts all the time....but who does that? Look at
SAP and their "dead" parts....there is no *point* in copying a dead part
but if you don't you will end up in a world of hurt...

Sometimes I think it would even be better to *not* have a consistant point
of recovery a "live with the risk"...but then I am described as being a
happy go lucky kind of guy who likes beer and sausages....with an
irrational dislike of 4000 partition databases!



Roy Boxwell
SOFTWARE ENGINEERING GMBH
-Product Development-
Robert-Stolz-Straße 5
40470 Düsseldorf/Germany
Tel. +49 (0)211 96149-675
Fax +49 (0)211 96149-32
Email: [login to unmask email]
http://www.seg.de

Software Engineering GmbH
Amtsgericht Düsseldorf, HRB 37894
Geschäftsführung: Siegfried Fürst, Gerhard Schubert





Olle Brostrom <[login to unmask email]>
Gesendet von: DB2 Data Base Discussion List <[login to unmask email]>
30.01.2009 10:31
Bitte antworten an DB2 Database Discussion list at IDUG


An: [login to unmask email]
Kopie:
Thema: [DB2-L] SV: [DB2-L] Antwort: [DB2-L] partitioning in V8


Hi Roy,
I don't agree with you about the mess you talk about.
We have a lot of partitioned TS and we almost always take image copies on
the part level and the running MODIFY RECOVERY once a week like this:
LISTDEF MODR0001 INCLUDE TABLESPACE XXXXXXX.YYYYYYY
MODIFY RECOVERY LIST MODR0001 DELETE AGE(40)
We then have no recovery info in SYSCOPY/SYSLGRNX older than 40 days
But if you run MODIFY RECOVERY on partlevel, then you will get
problem......

Best Regards
Olle Broström

Från: DB2 Data Base Discussion List [mailto:[login to unmask email] För Roy Boxwell
Skickat: den 30 januari 2009 07:46
Till: [login to unmask email]
Ämne: [DB2-L] Antwort: [DB2-L] partitioning in V8


and two little extra things to worry/think about...recovery and
reorg...With 1000's of partitions you would probably want to use TP level
image copies
now remember how Modify works with regard to deleting "old" data from
SYSIBM.SYSCOPY/LOGRNGX...That's right...it can only delete records when
there is a consistant point (Ie a DSNUM = 0 IC or perhaps all parts) this
means that you will have 1000's of basically useless image copies
filling up disk/tape space and SYSCOPY and LGRNGX as well...after a while
(Say a year) you have a HUGE mess and it takes *ages* to
do anything with it...As for reorg...well now with the "joy" of BUILD2
removal from 9 you cannot even do parallel REORGS anymore...yep..you gotta
serially
run your reorgs....if you have a NPI of course...but then who doesn't
still have a good-old-NPI hanging around the place? <sigh>



Roy Boxwell
SOFTWARE ENGINEERING GMBH
-Product Development-
Robert-Stolz-Straße 5
40470 Düsseldorf/Germany
Tel. +49 (0)211 96149-675
Fax +49 (0)211 96149-32
Email: [login to unmask email]
http://www.seg.de

Software Engineering GmbH
Amtsgericht Düsseldorf, HRB 37894
Geschäftsführung: Siegfried Fürst, Gerhard Schubert




Dave Magnusen <[login to unmask email]>
Gesendet von: DB2 Data Base Discussion List <[login to unmask email]>
29.01.2009 16:01
Bitte antworten an DB2 Database Discussion list at IDUG

An: [login to unmask email]
Kopie:
Thema: [DB2-L] partitioning in V8



As a relative newbie to DB2, and V8, please bear with me.

We have an application which would like to create many partitions.
Many thousand...
Has anyone partitioned to this level? Any horror stories, show-stoppers,
or
little gotcha's you can share are most appreciated.

Thanks,

dave

______________________________________________________________________

* IDUG 2009 Melbourne, Australia * 18-20 March * http://IDUG.ORG/Events *
______________________________________________________________________




IDUG.org was recently updated requiring members to use a new password. You
should have gotten an e-mail with the temporary password assigned to your
account. Please log in and update your member profile. If you are not
already an IDUG.org member, please register at
http://www.idug.org/component/juser/register.html




IDUG 2009 - Australasia * 18-20 March * Melbourne, Australia
IDUG.org was recently updated requiring members to use a new password. You should
have gotten an e-mail with the temporary password assigned to your
account. Please log in and update your member profile. If you are not
already an IDUG.org member, please register here.


IDUG 2009 - Australasia * 18-20 March * Melbourne, Australia
IDUG.org was recently updated requiring members to use a new password. You should
have gotten an e-mail with the temporary password assigned to your
account. Please log in and update your member profile. If you are not
already an IDUG.org member, please register here.



______________________________________________________________________

* IDUG 2009 Rome, Italy * 5-9 October * http://IDUG.ORG/Events *
______________________________________________________________________



IDUG.org was recently updated requiring members to use a new password. You should have gotten an e-mail with the temporary password assigned to your account. Please log in and update your member profile. If you are not already an IDUG.org member, please register at http://www.idug.org/component/juser/register.html

Michael Ebert

Re: SV: [DB2-L] Antwort: [DB2-L] partitioning in V8
(in response to Roy Boxwell)
The reply from Roy Boxwell is wrong. MODIFY does not require a consistency
point, and certainly not a table-wide one for partitioned tables. If you
do an image copy by partition, then you can run a MODIFY by partition, and
treat all partitions as independent tablespaces. There is only a "gotcha"
if you mix full-table ICs (DSNUM 0) and partition-level ones: you can't
run a partition-level MODIFY with an age that is less than the age of the
DSNUM 0 copy (because then you'd be deleting recovery info in LOGRNGX that
would be required for a recovery of the DSNUM 0 IC). Also, if you copy by
partition, you have to recover by partition (at least up to V7...).

We've had many partitioned tables, where each partition kept one day or
one month of data. The oldest partition would hold data that was 5 years
old, and there'd be only one similarly aged IC in SYSCOPY for that one
(actually I'd redo the copy every 15 months or so, before the TMS
scratched the tape); while the newest partition for the current month
would be LOADed and ICed every day, and have dozens of entries - none
older than a month. The procedure from Olle Brostrom has the disadvantage
that you do need to copy all partitions continuously whether or not
they're changed; otherwise the MODIFY might suddenly leave some of then in
COPYP state. If you do a partition-level COPY, you should do a
partition-level MODIFY, especially if (as in our case) the partitions are
not all updated equally.

Dr. Michael Ebert
DB2 & Oracle Database Administrator
aMaDEUS Data Processing
Erding / Munich, Germany




Olle Brostrom <[login to unmask email]>
To
[login to unmask email]
cc

bcc

Subject
[DB2-L] SV: [DB2-L] Antwort: [DB2-L] partitioning in V8





Olle Brostrom <[login to unmask email]>
Please respond to : DB2 Database Discussion list at IDUG
<[login to unmask email]>
Sent by: DB2 Data Base Discussion List <[login to unmask email]>
30-01-09 10:31


Hi Roy,
I don't agree with you about the mess you talk about.
We have a lot of partitioned TS and we almost always take image copies on
the part level and the running MODIFY RECOVERY once a week like this:
LISTDEF MODR0001 INCLUDE TABLESPACE XXXXXXX.YYYYYYY
MODIFY RECOVERY LIST MODR0001 DELETE AGE(40)
We then have no recovery info in SYSCOPY/SYSLGRNX older than 40 days
But if you run MODIFY RECOVERY on partlevel, then you will get
problem......

Best Regards
Olle Broström

Från: DB2 Data Base Discussion List [mailto:[login to unmask email] För Roy
Boxwell
Skickat: den 30 januari 2009 07:46
Till: [login to unmask email]
Ämne: [DB2-L] Antwort: [DB2-L] partitioning in V8


and two little extra things to worry/think about...recovery and
reorg...With 1000's of partitions you would probably want to use TP level
image copies
now remember how Modify works with regard to deleting "old" data from
SYSIBM.SYSCOPY/LOGRNGX...That's right...it can only delete records when
there is a consistant point (Ie a DSNUM = 0 IC or perhaps all parts) this
means that you will have 1000's of basically useless image copies
filling up disk/tape space and SYSCOPY and LGRNGX as well...after a while
(Say a year) you have a HUGE mess and it takes *ages* to
do anything with it...As for reorg...well now with the "joy" of BUILD2
removal from 9 you cannot even do parallel REORGS anymore...yep..you gotta
serially
run your reorgs....if you have a NPI of course...but then who doesn't
still have a good-old-NPI hanging around the place? <sigh>



Roy Boxwell
SOFTWARE ENGINEERING GMBH
-Product Development-
Robert-Stolz-Straße 5
40470 Düsseldorf/Germany
Tel. +49 (0)211 96149-675
Fax +49 (0)211 96149-32
Email: [login to unmask email]
http://www.seg.de

Software Engineering GmbH
Amtsgericht Düsseldorf, HRB 37894
Geschäftsführung: Siegfried Fürst, Gerhard Schubert




Dave Magnusen <[login to unmask email]>
Gesendet von: DB2 Data Base Discussion List <[login to unmask email]>
29.01.2009 16:01
Bitte antworten an DB2 Database Discussion list at IDUG

An: [login to unmask email]
Kopie:
Thema: [DB2-L] partitioning in V8



As a relative newbie to DB2, and V8, please bear with me.

We have an application which would like to create many partitions.
Many thousand...
Has anyone partitioned to this level? Any horror stories, show-stoppers,
or
little gotcha's you can share are most appreciated.

Thanks,

dave






IMPORTANT - CONFIDENTIALITY NOTICE - This e-mail is intended only for
the use of the individual or entity shown above as addressees. It may
contain information which is privileged, confidential or otherwise
protected from disclosure under applicable laws. If the reader of this
transmission is not the intended recipient, you are hereby notified that
any dissemination, printing, distribution, copying, disclosure or the
taking of any action in reliance on the contents of this information is
strictly prohibited. If you have received this transmission in error,
please immediately notify us by reply e-mail or using the address below
and delete the message and any attachments from your system.

Amadeus Data Processing GmbH
Geschäftsführer: Eberhard Haag
Sitz der Gesellschaft: Erding
HR München 48 199
Berghamer Strasse 6
85435 Erding
Germany


______________________________________________________________________

* IDUG 2009 Rome, Italy * 5-9 October * http://IDUG.ORG/Events *
______________________________________________________________________



IDUG.org was recently updated requiring members to use a new password. You should have gotten an e-mail with the temporary password assigned to your account. Please log in and update your member profile. If you are not already an IDUG.org member, please register at http://www.idug.org/component/juser/register.html