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Old 02-27-2008, 07:57 AM
jane
 
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Default Re: about multiple fact tables and star schema


Serge Rielau wrote:
> Jane,
>
> Which version of DB2, which platform?
> In DB2 9 you can easily use range partitioning.
> In both DB2 V8 and DB2 multi dimensional clustering may apply.
>
> UNION ALL view would be my last choice.
> Even 4KB Pages give you up to 64GB on DB2 V8.
> How much headroom do you need?
>
> Cheers
> Serge
> --
> Serge Rielau
> DB2 Solutions Development
> IBM Toronto Lab
>
> IOD Conference
> http://www.ibm.com/software/data/ond...ness/conf2006/


Thanks, Serge.

Probably I did not explain my question clearly.

My environment is UDB V8 on AIX.

My concern is not table size limit. Because now I know the Max size
for the big table is 40GB. It is OK on single partition, even for 4K
page.

My concern is on query performance. I know if using multi-partition, it
must be resolved.
but the other tables are all very small, and the total DB size is not
big (50GB), based on the DB size, I want to use single partition
database. Only because of this big table to use multi-partiton , seems
a little bit waste..

That's why I want to break down the big table to relatively smaller
ones. Use union all view.

One of my colleague remind me this would change optimizer to not use
star schema to get good access plan..
(because currently , the big table is fact table, it is in star schema
model)
I'm not sure if this is the case..

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