CLOB effects on a Coupling Facility

Robert Glover

CLOB effects on a Coupling Facility
We run a mixed V81 environemnt (CMP/NFM). We will soon be introducing
CLOBs into a data sharing environment. Does anyone who has done this
know how to calculate the Coupling Facility storage needs for CLOBS ?
What other types of fallout should I be looking for?

Thanks.

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Robert Catterall

Re: CLOB effects on a Coupling Facility
(in response to Robert Glover)
For a LOB tablespace, the default value for the GBPCACHE option is SYSTEM.
With this GBPCACHE value in effect (and it is only valid for a LOB
tablespace), only changed system pages (space map pages and other pages that
don't contain actual LOB data) will be written to the associated group
buffer pool in the coupling facility. There is a formula for calculating the
size of a group buffer pool needed to hold LOB tablespace system pages
(assuming GBPCACHE SYSTEM is in effect for a LOB tablespace) in the DB2 for
z/OS V8 Data Sharing Planning and Administration Guide. Here's a link to
that sizing formula:

http://publib.boulder.ibm.com/cgi-bin/bookmgr/BOOKS/dsndsj16/2.4.2.4?SHELF=&DT=20090527032249&CASE=

You shouldn't need to change the size of your lock structure and your SCA as
a result of introducing CLOBs to the mix.

Robert


On Tue, Jan 5, 2010 at 10:54 AM, Robert Glover <[login to unmask email]>wrote:

> We run a mixed V81 environemnt (CMP/NFM). We will soon be introducing
> CLOBs into a data sharing environment. Does anyone who has done this
> know how to calculate the Coupling Facility storage needs for CLOBS ?
> What other types of fallout should I be looking for?
>
> Thanks.
>
> _____________________________________________________________________
>
> * IDUG North America * Tampa, Florida, * May 10-14 2010 *
> http://IDUG.ORG/NA *
> _____________________________________________________________________
>
> http://www.IDUG.org membership is now free.
> Do you have people in your office who are not an IDUG member?
> Show them how to access the information and help train the next generation
> of DB2 Users!
> _____________________________________________________________________
>
> If you need to change settings, http://www.idug.org/cgi-bin/wa?A0=DB2-L is
> the home of IDUG's DB2-L
>



--
Robert Catterall
Catterall Consulting
www.catterallconsulting.com

_____________________________________________________________________

* IDUG North America * Tampa, Florida, * May 10-14 2010 * http://IDUG.ORG/NA *
_____________________________________________________________________

http://www.IDUG.org membership is now free.
Do you have people in your office who are not an IDUG member?
Show them how to access the information and help train the next generation of DB2 Users!
_____________________________________________________________________

If you need to change settings, http://www.idug.org/cgi-bin/wa?A0=DB2-L is the home of IDUG's DB2-L